THE GENUS

1897.]

A

REVISION OF

THE GENUS

SYNIDOTEA.*

BY JAMES

E. BENEDICT, ^PH.D.

Among

^the

^unnamed

IsopodsⁱⁿtheNational

Museum

seven _spe- ciesregarded ^as

new have

been referred toSynidotea^asdefined

by

Harger.

Of

the _eight described_speciesof the genus,^five were in the collection

and

anadditional onewas loaned

by

the California

Academy

^{of Sciences.}

With

so

many

new,

and

six of the_{eight de-} scribed _speciesat hand,^itwas thoughtbest to treatthe genus

mono-

graphically, and thedescriptions of the two remainingspecies were added.

The new

_species all

come

from the

North

Pacific

Ocean

andBer- ing ^Sea.

One was

taken in

San

Francisco

Bay by Mr.

^C.

H.

Townsend

whileexaminingthe oysterbedsforthe

U.

S. Fish

Com-

mission; the others were dredged

by

^the

'

Albatross,' oneoffthe State of

Washington and

^fivein Bering Sea^; twoof thelatterhad, however, previouslybeen taken

by Mr. W. H.

Dall.

The

bathymetrical range ^{of the} genus^isfrom shallowwaterto 695fathoms.

The

geographicalrange^{is asfollows:}

One

_{species in} South African _waters,onefrom Japan, one from

Lower

California, two fromCalifornia, oneoffthe State ofWashington,^{seven in} Ber- ingSea

and

the adjacent waters of the ArcticOcean, and two from the

North

Atlantic.

The

_{genusSynidotea}was instituted

by Harger

^{in1878 to receive} Idotea bieuspida

Owen and

/. nodulosa _Krjzfyer.

The

two _species

now

represent thetwo sectionsof the genus^; the bieuspida ^section contains eleven

and

the nodulosa four_species. Allof the _species

come

well within thelimitsof the genus.

The

antennre ofallhave multi-articulate_flagella.

The

_palpusof the maxillipeds has butthree _joints.

The

_epimera of the four an- teriorsegments^areindicated,^ifat_all,

by

^aslightnotchorpitinthe posterior margins

midway

^{between the lateral} margins

and

the

median

line_; the epimera of the three _posteriorsegments ^{are dis-} tinctly outlinedin adorsal view,and are _solidlyunited tothe true

* Publishedbypermission^ofthe Secretary^oftheSmithsonianInstitution.

26

[1897.

segmental margins.

The abdomen

is composed ^of two segments united above but_separated atthesidesby ^{short incisions.}

In addition to theabove_generic characters, most_{species agree}in having ^thehead excavatedin front,a cross-like areolation between the_eyes, the extremities of the crossbeing usually

armed

withtuber- clesor spines^; in having^a spineor tubercle between _{the eyes} and thefront.

A

_deeptransversesuture near the backofthehead cuts off a postcephalic lobe or ^areolation; between this areolation and the cross are two lateral areolations,sometimes united atthe base and sometimes _separated by ^achannel.

The

sides of thethorax in all speciesshowundulations or nodules of

more

orless prominence.

The

section of thegenus ^ofwhich _bicuspidais thetype ^is charac- terized by having ^{the distal} end of the

abdomen

_emarginateorbi- cuspid,whilein thenodulosa sectionthe end^is _{bluntly pointed.}

The

basal plates of theoperculum^{in all}species except harfordi are crossed

by

a diagonal^lineor ridge.

SYNIDOTEA

_Harger.

Synidotea Harger,AmericanJournalofScience_(3),

XV,

p. 374, 1878.

EdotiaMiers, Journal Linn.Soc. Lond., XVI, p.65 _(pars),¹ 1883.

Synidotea G. O. Sars,Norwegian NorthAtlantic Expedition,Crust., p. 116, 1885.

SynidoteaHarger, characteremended.

"Antenna? with an articulated flagellum." Epimeral^{sutures not} evident above on thefirstfour segments; on the ^lastthreethelines ofdemarcation are

more

or less distinct. "

Pleon _apparentlycom- posed of two segments, united above but separated ^{at the sides} by short incisions.

Operculum

^{with a}single apical plate. Palpus ^of maxillipedsthree-jointed."

1Miers,in his "RevisionoftheIdoteidre"inthis journal, unites several genera under Edotia Guerin-Meneville, then arranges Edotia ^{in three sec-} tions as follows^:

#Antenmvwell developed, with the flagellum composed^{of several}joints.

Postabdomenuniarticulate. (Synidotea).

'0.Antenna? verysmall,with the_flagellumrudimentary^; postabdomen^uni- articulate. (Edotia).

§§|Flagellum^oftheantenna; obsolete;postabdomenbiarticulate.(Desmares-

lia, Epelys.⁾

In thisarrangement Professor ^Sars does not concur,but_saysinregard ^to Synidotea,^"This genus was^{firstinstituted}byHarger,andshould unquestion- ably be maintained."

1897.]

Key

^to Species Examined.

a

Abdomen

_emarginateor notched at thedistal end.

b

Two

_spinesor tubercles overhanging ^thefrontal notch.

c Spines united near the ^base. pallida

c' Tubercles free atthebase. erosa

b'

No

_{spines or}tuberclesoverhanging^{the frontal notch.}

c

With

a low _{ridge arising} between _{the eyes}and interrupted on the

median

line.

d Outlines of

abdomen

subparallel. nebulosa d' Outlines strongly^arcuate. angulata

c'

Without

_{a ridge}between the _eyes.

d Outline of

abdomen

subtriangular.

e Front not excavated. ^*consolidata e' Frontexcavated.

f Outlines ofthorax subparallel. marmorata

f

Outlines ofthorax _strongly arcuate.

bicuspida d' Outlines of

abdomen

rounded.

e

Length

^of

abdomen

_equal to width at base.

laticauda

e'

Length

^of

abdomen

_equal to one and one-half times thewidth at base. harfordi

a'

Abdomen

_pointed.

b Undulations of the

body

not tubercular_{or spiny.}

c Tubercle in frontof the eyes not margined. ^nodulosa

c' Tubercle on thefrontalmargin

and

_{forminga part of} it.

Icevis b' Undulations of the

body

^{tubercularand}spiny.

c

Four

_spines on thefrontofthe head;

body

spinous.

m

uricata c'

A

wedge-shaped ^tubercle behind the frontal notch_;

body

tubercular. _picta

Synidotea bicuspida(Owen). Fig.^1.

Idotea bicuspidaOwen, ^{Crustaceaof the}

'

Blossom,'p. 92,_pi. xxvii, fig. 6, 1839.

Idoteapulchra Lockington, Proc. ^Cali-Acad. Sci.,VII. p. 44, 1877.

Edotia bicuspida Miers, Journal^ofthe Linnean _{Society of} London,XVI,

p.66, 1883 _(pars).

Synidotea bicuspidaSars, Crustacea,Norwegian North^AtlanticExped^,p.

116, _pi. X, figs. 24-26, 1885; equal ^to Synidotea incisa Sars,Crustaceaet

Pycnogonida^nova,etc.,No. 8.

[1897.

Fig. ^1. Synidotea bicuspida (Owen),

xf

There are a _large

number

of_speci-

mens

of this speciesⁱⁿ the collection from Bering Sea and^{the Arctic}Ocean.

The

_speciesis the_largest and itsshell isthe heaviest

and

strongest ofanyⁱⁿ the geuus. This

and

the _closely re- lated Atlantic form, ^S. marmorata Packard, and the small Californian species ^S. consolidata (Stimpson), are easily distinguished from any

known

species

by

^the triangular

abdomen

with a comparatively sharp bicuspid apex.

Some

of the _largest specimens measure31

mm.

ⁱⁿ_length and 14.5 in width.

Shallowwater to56 fathoms.

Synidoteamarmorata_(Packard). Fig.^2.

Idotsea marmorata Packard, MemoirsBoston Society^ofNatural _History,

I, p. 296,pi.viii, fig.6,1867. Whiteaves, Canad. Nat.,p. 262. 1875.

Idotea'marmorata_equalsI. bicuspida Streetsand_Kingsley,Bulletin Essex Institute,IX,p. 108, 1877.

?IdotJiearugulosa Buehholz, ZweiteDeutsche Nordpolarf.,II, p.285, 1874.

Synidotea bimspida Harger, Proceedings ^{U. S.} National Museum,II, p.

160, 1879; ^also U.S. FishCommission Keportfor 1878, p. 352, 1880.

Edotiabicuspida Miers, Jour. Linn.Soc. Loud.,XVI,p. 06,1SS3 _(pars).

This_species was describedby A.

S. Packard, Jr.,in hispaper on ^the

"

RecentInvertebrate

Fauna

ofLa- brador^" from specimens taken ⁱⁿ

Kyuetarbuck Bay

^{inseven fathoms} on asandy ^bottom.

The

National

Museum

seriesconsistsof four_spec- imens from Station _2,431, lat. N.

43° 00' 00", ^Ion.

W.

50° 47' 30", 129 fathoms; one from Station 2,436, ^lat. N. 43° 36' 00",^Ion.

W.

50° 06' 30",36 fathoms, and five

from

the Gloucester fishermen.

Compared

^{with S.} bicuspida ^{it is} not so wide; the thinepimeralpro- jections so prominent ⁱⁿ bicuspida are

much

reduced in this species;

the_joints of the antenna?are _relativelylonger and

more

slenderin marmorata.

The

_averagesizeof thespecimens^ofmarmoratais

much

Fig.^2. Synidoteamarmorata Packard, x2h.

1897.]

smallerthan those of bicuspida; ^a larger ^series might change ^this.

The

_largest male S.marmorata measures 18

mm.

ⁱⁿ _length and 7

mm.

ⁱⁿ width.

A

maleS. bicuspida of about _equal size, measures 17

mm.

in length and 8in width.

Synidoteaconsolidata (Stimpson). Fig.^3.

Idotea consolidata Stimpson, Proc Cal. Acad. Sci, I, p. (89) 97, 1856, alsoBostonJour.Nat._Hist.,VI,p.503, 1857.

Edotia _bicuspida(nee^IdoteabicuspidaOwen)Miers,Jour. Linn.Soc.Lond., XVI,p. 66, 1883(pars).

Two

_specimens of this species, labelled 'Pacific Grove, California,' were received from Mr. J. O. _Snyder.

The

front isemarginate, themediannotch

islarge.

The

_deep excavation of the front in S.bicuspida ^{is in} sharp ^{contrast to the} nearly straight front of this species. Be- hind the frontal notch is a pair of _large, blunt tubercles transversely placed.

The

lateral margins^ofthethoraxaresubparallel in the male and strongly arcuate ⁱⁿthe fe-

male.

The

_margins are incisedin this spe- cies_; in bicuspidathey^{are full.} Thereisa line oflow_swellings onthe median lineand

another line of like swellings part

way

^be- Fig ^3. Synidotea ^con- tween the median lineandthe margin.

The

^solidata (Stimpson). xf.*

abdomen

is

much

like that of_bicuspida.

Synidotealaticauda,new_{species. Fig.}4.

A

_{single specimen} of Synidotea was taken by Mr. ^C.

H. Townseud

in San Francisco

Bay

^{; it is}readily distinguished from anyspecies yet described.

The

headis wider than _long,the anterior margin ^is nearly straight and is slightly produced ^horizon-

tally^{; its} whole upper ^{surface is} evenly swollen

and

has neither ele- vationsnordepressions ofany kind^; the cephalic lobe^islittle

more

than indicated.

The

_eyes are _large, round, ^lateraland butvery slightly projecting.

The

antenna? are equal Fig.^4. Synidotea laticauda

Benedict, x2J

*_Incorrect. The antennae should be placed ^{as in} the others and show sevenor eight joints inthe_flagella.

[1897.

tothehead and thorax inlength,the flagellum has twenty-one ^arti-

cles.

The

basal segment ^{of the} peduncle^isshort, reaching but a

little beyond ^{the front; the second} segment ^{is as} broad as long;

the third segment ^is about once anda half aslong ^asbroad; the fourthis alittle

more

than twice the breadth; the fifth isnearly ^as long^as thethird andfourth _together.

The

antennulse extend alit- tle

beyond

^{the base ofthe fourth}segment^{oftheantenna?.}

The

thoraxis widest atthe fourth segment.

From

the sides of the fourth segment ^{the outline curves} around totheeye. Poste- riorlyfrom the fourth segment ^{the outlineis}straight^to the distal third of the abdomen.

The

second,^third and fourth segments^are longest. There are no _spinesor tuberclesanywhere and ^the rugos- itiesso

common

^tothespecies ofthegenus ^arebarely^indicated.

The abdomen

^is_very ^little longer than its breadth at the base.

Ittapersgradually^for the firsttwo-thirds of itslength whereitbe- gins^totaper

more

_rapidly to abroad emarginate extremity.

The

feet are sparsely^set with coarse hair.

The

valves of the operculum are diagonally ^crossed

by

^{a curved line.}

The

_specimen ^is clouded with dark _patches

made

_up of small black_spots.

This _speciescan be distinguishedfrom anyother yet described

by

itsbroadly emarginate abdomen.

Length

¹⁷

mm.,

^{width 7}

mm.

_{(No. 20,504,} U.S.N. _M.).

Synidotea^nebulosa,new_{species. Fig.}5.

The

front of thehead is exca- vated; betweenthe median notch and theantero-lateral margin ^the outline isemarginate^; betweenthe margin and the eyes the protuber- ancesare but little elevated_; the cross areolation ^issmooth; thelat- eral areolations are separated by an extension of the cross_; thisex- tension isitselfslightlydivided by a_slightlyimpressed ^line.

The

de- pression ⁱⁿ front of the _postce- phalic lobe^isdeep.

The

sides of the head extend to the vertical line of the_eyes, cutting ^off thevi- sion from _{objects directly} below.

The

antennae areabout 6

mm.

in Benedict.

Fig.^5. Synidotea ^nebulosa

1897.]

length ⁱⁿ a large specimen

and

have aten-jointed flagellum^; the distaljoint ofthe peduncle ^is1.5

mm.

in length.

The

outlineof the thorax ^is ovate in both sexes; the undulations are distinct; the fourth segment ^isthe longest.

The

epimeral sutures of the three posterior segments^{can be}

made

outundera lens.

The

incisions on the sides of the

abdomen

are short; the areolations at the base

and summit

are _large and smooth.

The

lateral outline of the anterior half isstraightor_slightly concave, of the _posterior half convex.

The

distal end ^is _slightlyexcavated.

Several specimens ^of both sexes were takenatStation 3,600 ⁱⁿ

company

^{with S.} picta, and at Station 3,637 ⁱⁿ 32 fathoms. Mr.

Dall obtained them at

Unalaska

ⁱⁿ 16fathoms; at

Kyska

^Harbor,

9 to 16 fathoms; Semidi Islands, 12 to 25 fathoms. Types (No.

20,503, U. S. N. M.) from ^Station 3,600, ^lat. N. 55° 06' 00", ^Ion.

W.

163° 28' 00",9 fathoms.

This_species can be distinguished at sightfromall otheralcoholic specimens^{of the} genus

by

^itsdark-coloredhead

and

fourth segment, and by^the dark linesurroundingthe elevated portions of the abdo- men.

The

first

and

lastthreesegments ^{of the}thorax are _lightwith small flakes of black uniformly sprinkled over the surface; the median lineof thefirstthree isusually broad

and

dark.

Length

of a large male, 17

mm.

; width, ^6.5

mm.

_Length of a largefemale, 15

mm.

; width, ⁷

mm.

Synidotea angulata,new_{species. Fig.}6.

This is a small _{species easily} distin- guished from the others of thegenus ⁱⁿ

its region by ^the angular andprojecting lateral margins^{of the firstthreethoracic} segments^{; it is}most_nearlyrelated to S.

nebulosa.

The

head is excavated in front in a nearlyeven curve, and there is no dis- tinct median notch asin nebulosa. Be- tween _{the eyes}and thefront the tuber- cles are very low and inconspicuous^; thecross areolationis a low ridge ^inter- rupted ⁱⁿ the middle by ^a V-shaped notch; the lateral areolations of other species, in _this, form a _single transverse areolation notatall separated ⁱⁿ the middle; it isseparated from the postcephalic lobe

by

^adeep impression.

The

sidesof the head

Fig.^6. Synidotea angulata Benedict, x

.

[1897.

donotextend tothe vertical lineof the_eyes.

The

flagellum of the antenna? has nine or ten _joints.

The

sidesof the thorax arevery

much

less arcuatethan innebulosa, and wherein the latter species the margins are rounded, ^{in this}theyproject inobtuse angles; the lateral margins of the three _posterior segments^arestraight.

The abdomen

is very,

much

asinnebulosa. In colorthisspeciesⁱⁿ part simulates nebulosa. In the specimens examined itlacks the black flakes, thereis a lineof _spotsnear the margin and one ^{in linewith} the epimeral ^lines.

The

_largestgood specimen ^{is 11}

mm.

in length.

Stations 2,868,2,869 and _2,872,in 31 to38 fathoms.

Station_2,869, lat.N. 47° 38' 00", ^Ion.

W.

124°39'00"; 32 fath- oms. Types(No. 20,506,

U.

S. N. _M.).

Synidoteapallida,new_species. Fig.^7.

The

frontal margin ^isdeeply and evenly concave, there being no median notch.

The

surface between _{the eyes}isprotuberant and is divided by ^a slight me- dian impressed ^line. In the angleformed by^{the raised} por- tion between the _eyes and the horizontal front are two horn- like tuberclesunitedatthebases

by

^a very^shortridge ^acrossthe median line.

The

_cephalicsu- ture is deep ^{but closed at tlie} bottom.

The

peduncles of the antenna? areabout_equal tothe flagella ⁱⁿ length^; the latter have from 12 to 16 segments.

The

_eyesaresmall, situated ata distance from the margin on

slight elevations.

The

sidesof the head

and

ofall thethoricic_seg- mentsarethin andproduced, nearly horizontal.

The

four anterior segments ^are long,with rounded post-lateral angles,the _{three pos-} teriorsegments^{areshort with subacute} angles.

On

each side ata

little distancefrom the

median

lineon the _2d,3d and 4thsegments

isa single spine. In

young

specimens ^the spines are proportion- atelylonger and_theyarereplaced on the posteriorsegments by low

Fig.^7. Synidoteapallida Benedict.

x2J.

1897.]

tubercles; the median lineisalsotubercular.

The

_{legsare long}and slenderon the7th segment, a ^little shorteron _{the 6th,} and soon to the 1stwhich arequite short.

The abdomen

is markedly narrower than the 7th segment,^it tap- ers gradually^to a point near the end which is broad and well rounded, the median lineendsin a small concavity^bestseen with a lens. Excepting ^{the usual lateral} incisions, the upper ^{surface is} smooth and_glabrous.

A

_large male measures 22

mm.

in length and 7.5 in breadth; a female, with eggs,12

mm.

in length and 4.5 in breadth.

Not

lessthanone thousand specimens ^ofthis species were dredged

off Chirikoff _Island, Alaska, ^{at Station} 3,340,^lat. N. 55° 26' 00", Ion.

W.

155° 26' 00", 695 fathoms (No. 20,500, U. S. N. _M.).

Synidoteaerosa,new_{species. Fig.}8.

Several specimens ^{of this} species were dredged ^atStation 3,210^oft* San-

nakh

_{Islands, Alaska,} in483 fathoms_;

lat. N. 54° 00' 00", ^Ion.

W.

162° 40' 30" (No. 20,505,U. S. N._M.).

Erosa is

more

_nearly related to S.

pallida than to

any

species yet ^dis- covered,^{as in} the latterthere are two horn-like protuberances just back of thefrontal margin.

The

_cephalic su- ture isthe

same

_except that it is

more

open ^{at the bottom.}

The

other_pro- tuberances

and

depressions of the head are thesame, except^{thatin erosa,}there

is a prominent ^tubercle between the eyes

and

the front; in S.pallida^this

islacking, ^{or, if} represented ^atall,

by

a low_swelling. All of the projections of the head are

more

orless eroded.

The

_segments of the thorax have_very low tuberclesor slight swellings wherethe_spinesaresitu- ated in pallida.

The

_rugse of the lowest portions of thethorax are

much more

_prominent in this species. In outline erosa isnarrower

and

less arcuate, the outer margins^{of the} segments ^are

much

less produced.

The

7th segment^isnot noticeably wider thanthe base of the abdomen.

The abdomen

holds its widthto a pointbeyond the middle,

whence

it is rounded to the terminus, which, ^{as in}

Fig. ^8. Synidotea^erosa Benedict.

r

PROCEEDINGS OF OF

_[1897.

pallida, ^is slightly concave.

The

_slightly arcuate outline of the thorax running ^{into the}straight outline of the

abdomen

differenti- ates thisfromall other_species of the genus. Other differences_are, the larger eyes ^situated nearer the margin of the head, thevery hairy edges of thevalve,

and

the sparsely granulatedabdomen.

The

length of the adults fromwhich the foregoing description ^is

made

rangesfrom21 to22

mm.

A

female, about 14

mm.

in length, has arcuate lateral margins, and all of thetuberclesof the largemale are exaggerated^insize; thetubercles between _{the eyes} and thefrontand the pair separated

by

^{themedianlineforma}

row

of four large tuberclesonthe front.

The _young

maleshave almost _parallel sides_; the median tuber- cles of the front are swollen and

much

eroded, ^as are allof the prominences^ofthehead.

On

each of thefirstfoursegments^{of the} thorax is a median tubercle on the transverse ridge and also a smaller onein frontofit; there isanotherrow of tuberclesonthe sides.

The

sidesofthe

abdomen

are rough and warty.

Synidotea nodulosa(Kr/yer).

The

limitsof this species are hard todefine. All of the _species with pointed

abdomens

are very^similar,yet constitute, I believe, goodspecies.

Abundant

material will not unlikely

show

that addi- tional species must berecognized.

Kr^yer

^{describednodulosafrom} South Greenland;

Harger had

^severalspecimensfrom the Eastern Fishing

Banks and

also records

them

from off

Queen

^Charlotte

Island.

Ihavenotfoundnodulosainthewestcoast collections.

A

_dryspe-

cimen from Jugor Scharpresentedby^the

Royal

Zoological

Museum

of

Copenhagen

^{has the cross areolation between} the eyes

armed

with four_tubercles, thetwo on the transverseline are_slightlycom- pressed, thoseon the median lineare united atthebase,the _poste- rior one is

much

the larger; the areolations between the _post- cephalic lobe and the cross are well elevated, coarsely punctate, anddivided on themedian line_; the tubercles betweenthemargin

and

the eyes are^wellelevatedand freefromthe margin.

On

each segment ^{of the}thorax ashort ridge ^crossesthe

median

_line,form- ing a slightly elevated angular ^tubercle on the line.

The

abdo-

men

measures^atthe base aboutfour-fifthsof itslength, or4.2

mm.

broad to 5.3 long.

A

specimen from ^thefishingbanksof the northeast coastisprob- ably nearerKr^fyer'stypethan any^{otherinthe collection; inthis} thecrossis

armed

with four tuberclesthatare

much

lessconspicu-

1897.]

ous than those of the Jugor Schar specimen, the posterior oneon the median line isthe _largest andis notso positively united atthe base_; theareolations behind the cross are notso elevated,

and

are but_faintly punctate^{; in this}and in

some

smaller specimens they are unitedon the

median

line; thetubercles in frontofthe eyes are not so nearly^vertical and are

much more

_angular; thetransverse ridges are notso large but

more

acute, with slight tubercles at their ^inter- sectionwith the median line.

The abdomen

measures at its base 8.2

mm.

ⁱⁿ breadth, ^its length ^is4.25

mm.

In8.Icevisthe cross is

armed

with buta _single tubercle on the

median

line_; this is not vertical as innodulosa, but horizontal,

and when

seen from above covers themediannotch of tbe _front,otherwise the cross isa smooth areolationwith _slightly elevated transverse extremities.

The

areo- lations behind the cross are smooth and broadly ^{united at the} median line.

The

tuberclesin front of the eyes^arisefrom the mar- gin and form _{a part of} it.

The

_segmentsof the thorax are incon- spicuously tubercular on the median line.

The

breadth of the

abdomen

at thebaseis 4 mm., length ^5.4

mm.

Synidotealaevis,new _{species. Fig.}9.

Numerous

specimens from ^Sta- tions 3,252,^lat.N. 57°22' 20",^Ion.

W.

164° 24' 40",29ifathoms,

and

3,253,^lat.

N.

57° 05' 50",^Ion.

W.

164° 27' 15",36 _{fathoms, respect-} ively,^differ from S. nodulosa

and

itsnear allies

by

^thelack of three tubercles on the head

and

the less

prominentelevations of thethorax.

The

cross-like areolation between the eyes^issmooth with the excep- tion of a _single tubercle which is

prolonged horizontally over the

median notch. The

tubercles which in nodulosa ^arise between the eyesand the_front, in this spe-

x ?•

cies arise atthe margin

and

form _{a part of} it.

They

^{areless erect} than in nodulosa and are

more

_angular.

Harger

says of nodulosa, ^"Color in alcohol gray, ^often with brownish transverse

markings;"

^these specimens aregray^{in alco-}

hol with a dark, broken, median line onthe anteriorsegments.

Fig. ^9. Synidotea ^laevisBenedict.

[1897.

Length ¹⁵ mm., breadth ^4.8

mm. _Types

_{(No. 20,501,}

U.

S.

N.

M.).

Synidotea muricata (Harford). Fig. in. Hotcea muricata Harford. Proc. Cal.

Acad. _Sei., VII, ^Pt.I, p.117, (1876), 1877.

Sixspecimens, takenby^the'Cor- win^' off Icy

Cape

^{differ from all} other _speciesof the genus yet ^de- scribedby the spiny nature of the dorsal surface, head and _pleon in- cluded.

The

_locality is lat. 70°

15' 00"_{N., long.} 162° 55'00" W., in 25 fathoms.

The

head is deeplyexcavatedin front, the margin running inward from the lateral prolongations^toa

median

notch.

The

_flagella of the antennjB have from 10 to 12 _seg- ments.

A

small spine overhangs the median _notch, asecond spine

issituated a littlebehind the _first, a thirdisin line on the _posterior lobe; two other_spines,oneoneach side of thefirst two, form,^{in con-} nection with them, thefigureofadiamond;the spinesof themedian line are atthe obtuse_angles.

A

little behind the margin and ⁱⁿ front of the eye^is ashort spine with a compressed ^base. Spines withcompressed ^{bases are}not peculiar ^tothe front,but begin on the postcephalic lobe and extend tothe end of the thorax situated on transverse _ridges and forming ^the median line of _spines.

The

spines on the

abdomen

are not compressed.

On

either side of the median lineisa lateral line of _spines; belowthese spines on each segment ^{is a}group^{of five} spines arranged ⁱⁿtwo transverse _rows, three in theanteriorand twoin the posterior rows.

The abdomen

has two transverse ridges, the basal ridge has three spinesand the next _ridge five.

On

each side is agroup^of from five to nine very short _spines,the

number

_{varying according} tothesizeof the _speci- men.

The abdomen

is broad at the base, constricted at about the middle and runs out to an acute terminus.

The

_specimens have been in poor alcohol ^too long^to

make

color notesof any ^value.

Length

^ofa large specimen ²¹ mm.,^{breadth 7}

mm.

Fig.^10. Synidotea muricata Harford, x2i.

1897.]

Fig. ^11. Synidoteapicta Benedict, x#.

Synidoteapicta,new_species. Figs. 11and12.

The

head is deeply excavated ⁱⁿ front; the notch isdeep^{; the tuber-}

cles in front of the eyes arenear to

and overhang^the margin.

The

^{median line of the}cross areo- lationis elevatedintoawedge-shaped ridgewhich overhangs^{the notchin a} verticalview; thetransverseextrem-

itiesofthe cross areelevatedforming tubercles; the lateral areolationsare protuberant

and

are separatedby ^a deep depressionwhich uniteswith the depression ⁱⁿ front of the _postce- phalic lobe

and

the one behind the cross, altogether forming^a

B

_shaped

depression.

The

elevated portions of

the head are_pitted.

The

flagellum of the antennae is composed^of eight or nine segments.

From

the anteriorangles the

body

^widens

to the fourth segment^; from this point^itdiminishes evenly ^{in size} to the end ofthe abdomen. All of thesegments have lowswellings on themedian line and

numerous

_rugositieson thesides.

The

ex- tremity of^the

abdomen

is pointed; the surfaceispunctate.

This _species is beautifully colored; the antennal peduncles ^are patched with dark, the anteriormargins^{of the}headare in

some

specimensblotched withrose; the_rugosities of thethorax are tinged with^red, the abdo-

men

^{is blotched Avith red and dark. In}

the

more

highly coloredspecimens^{the lower} portion of the segments ^are light

and

_red, except on the fourth whichis always ^dark.

The

_legs have_{a patch of}dark oneach_joint.

The

length of a largespecimen^is 14

mm.

The

seven type specimens were dredged at Station_3,600, lat.

N.

55°06' 00",^Ion.

W.

163° 28' 00", 9 fathoms,ⁱⁿ

company

^withS.

nebulosa (No. 20,502, U.S. N. _M.).

Variety.

—

_Specimensobtainedby Mr. Dall in Bering ^Strait (No.^13,311,

U.

S.N. _M.),

Fig. ^12. Synidoteapicta, var. x ^3._1*

[1897.

and at

Cape

^Lisburne (No. 13,325,

U.

S. N. M.) and by ^Lieutenant Stoney ⁱⁿ Norton

Sound

_{(No. 13,641,} U.S. N. _M.), differfrom the typesⁱⁿ having ^{a stouter}

abdomen

and a

much more

solid shell;

they ^also lack _color, not unlikely because of the greater length of time in alcohol. These _specimens

come

from localitiesfartothe north of the station where the_types wereobtained.

More

material in a fresh state

may

^{show sound lines of} demarcation that are not sufficientlyevident inthe material athand.

Synidoteaharfordi,newname. _Fig.13.

Idot&amarmoraia Harford, Proc.^Cal.Acad._Sci.,VII,p. 117, 1877.

The name

_given

_by

Mr. Harford was preoccupied by ^Professor

Packard

in 1867. (See p.392).

The

front of the head is nearly straight,the sides are bent abruptly

downward

and inward; the eyes are on the angle thus formed, extending the range of^{vision to}objects beneath.

The

length of the antennae ^{laid off}on the median linereachesfrom the front tothe middle of thesixth thoracic_seg-

ment

; the fifth joint of thepeduncle equals ⁱⁿ length the ^third and fourth taken together^; the flagellum has twenty-two segments.

The body

^{is widestatthesecondand}

third segments, tapering forward to the anterolateral angles of the head;

its anterior outlineis arcuate; poste- riorlythe

body

tapers^tothe endof the narrow

abdomen

in nearly straight

lines.

The

four anterior segments ^{are the} longest.

The

sur- face of the

body

^is finelypunctate under a lens.

The median

line of thethorax is dark-colored; on the second,third and fourth segments ^is a _light and _{slightly impressed} V-shaped ^line,the

V

opening forward^; onthesesegments^{there isalsoon eachsideofthe}

V

a diagonally-placed light spotshaped ^likea half-moon^: thesur- face iselsewhere _spotted and blotched with _lightand dark.

The

specimen^islabelled

'

Magdalena

Bay, ^L.

C,

^{"W.J. Fisher.'}

Length

^16.5 mm., breadth ⁵

mm.

Fig.^13. Synidotea harfordi Benedict, new name, x 3i.

1897.]

Synidoteahirtipes (Milne-Edwards).

Idotea _hirtipes Milne-Edwards, Hist. Nat. des _Crust., Ill, p. 134, 1S40.

Krauss,DieSudafrikan.Crust.,p. 61, 1843.

Edotiahirtipes Miers, Jour. Linn.Soc.Lond., XVI,p. 68, 1883.

Miers' description ofMilne-Edwards' _typeisas follows:

"

In thisspecies the

body

^is

somewhat

_ovate, moderately convex, arcuated on the sides, evenly granulated above, withlarge inequal-

itieson the sidesof the thoracicsegments ^at somedistancefrom the lateralmargins.

Head

with the anterior margin veryslightlyex- cavated, and with a semicircularcurved_impressed line posterior to itsfrontalmargin, and another, nearlystraight linenearits

posterior margin^{; its} antero-lateralanglesprominent

and

_nearlyright angles.

The

first three thoracicsegments ^with an _impressed curved linein the middleofthedorsal surface,and roundedattheir postero-lateral angles^{; in} none of the segments are these angles prolonged back- ward.

Postabdomen

short, rounded posteriorly, with a fissure on each ^{side at} its base,andwith a small

and

shallowmedian emargina- tion at itsdistal end.

Eyes

^{large. Antennules} reaching nearly ^to the end of the penultimate joint of the _antennse, with theirbasal joints very ^small. Terminal _jointof the peduncle ^of the antennse longer than the preceding^; flagellum withabout 14-21_joints.

Legs

long, slender, hairy,

and

terminating ⁱⁿ a long ^claw. Terminal plates of the opercular valves irregularly four-sided, being

much

narrowed atthe distal end.

Length

^{of the} largestspecimen nearly 1 inch _(2.5 mm.), breadth nearlytjinch (10 mm.)."

Localities,

Cape

^of

Good Hope

(Types)^; Simon's Bay, South Africa,ⁱⁿ4-7 fathoms.

Synidotealsevidorsalis_(Miers).

Edotia hirtipes,var.IsevidorsalisMiers,Jour.Linn.Soc. Lond.,

XVI,

p.69, pi. Ill,figs.1, 2,1883.

Miers _saysof this species "

Two

malesare inthe collection of the

Museum

from Jatiyama Bay, Japan, ^{obtained at a} depth ^{of 6i} fathoms, ^lat. 39° ^2'_{N., long.}189°50'_E.,presented by Dr. ^J.

Gwyn

Jeffreys and collected by Capt.

H.

C.St. John, ^B,. N., that^differ so slightly from I. hirtipesthatI cannot_regard

them

asspecifically distinct.

The body

^isquitesmoothin the largerexample, and very nearly ^{so in} the smaller(which^{is of} larger^sizethan any specimen of the _typical I. hirtipes that I have _seen), and in both ^is of a decidedly narrower-oval form; the antero-lateralangles of^thehead

[1897.

are perhaps ^{not so} prominent and

more

rounded; the _eyes are smaller.

Length

^{of the} largest

example

^{about 1} inch, ¹ line (28millim.)^; breadth abouttsinch (10 millim.). In thisspecimen the flagellum of the antennae^is about 30-jointed, butin thesmaller example (length ^f inch, 21 _millim.)only about21-jointed."