Two new Australian crinoids

Vol. XXII, ^pp. 39-42

March

_10,

1909

PROCEEDINGS

OKTHE

BIOLOGICAL SOCIETY OF WASHINGTON

TWO NEW AUSTRALIAN CRINOIDS.

BY AUSTIN H(3BART CLARK.

The

collections

made by

the

German steamship

^{Gazelle in}

the Australian

seas

included a number

of

unstalked

crinoids

taken on the

zoologically^little

known

coast of

West

Australia.

Through

the courtesy^of Drs.

W. Weltner and R. Hartmeyer

of the

Konigliche

Zoologisches

Museum

at Berlin,

and

of

Dr.

Th. Studer

of

Berne,

these crinoids

have been submitted

to

me

forstudy.

There

are

among them two

interesting

new

_species,

both belonging

^to characteristic littoral

East Indian

genera.

Ptilometra dorcadis sp. nov.

Antedon

macronema

1889. Studer, DieForschungsreise^S.

M.

S. Gazelle, III Thiel, p. 185.

Type.

—

Cat.No._2,964 (part), Kt5nio;licheZoologisches

Museum,

^Berlin.

Centro-dorsal columnar, ^{6.5 nun. in} diameter at the base

by

³

mm.

long, thesides slightlyconvex, ^thelarge polar areaflat, 5

mm.

indiame- ter; cirrussockets_closelycrowded, arranged^{in fifteen}columnsoftwoor three each, the socketsⁱⁿeach

column

_tendingtoalternateAviththosein theneighboring columns.

Cirri xxxv, 93, 55

mm.

to 60

mm.

_long, stout _basally, but _tapering distally; ^first joint very short, about four times as broad _{as long,} the followinggradually increasingⁱⁿlength ^toabout_{the eighth} to thirteenth,

which

^is squarish, then remaining ^{similar or} bec(jming very slightly longer than _broad, until about the thirty-fifth, then _{very gradually} decreasingⁱⁿlength, the terminalforty orsobeing about ^{twice as} broad as long; proximal joints smooth, without dorsal or ventral spines; ^at aboutthethirty-fifth the

median

distal dorsal border _begins to

become

prominent, ^this feature gradually

becoming more

pronounced, ^resulting indorsal spines on the later joints resembling ^{those of P.}

macronema;

opposingspinelarge, prominent, blunt, directed anteriorly, arisingfrom theentiredorsal surfaceof the ])enultimate joint, equal ⁱⁿ length ^to the anteriordiameterof that_joint; terminalclaw_nearlyas long ^as the two precedingjoints, slender, slightlycurved.

4—

Proc. Biol. Soc.Wash., Vol.XXII, 1909. (39)

40

Chirk

— _{Two New}

Australian Crinoids.

Disk

and

brachial ambulacra naked; coveri)io:

and

side plates well developed^{inthedistalhalf ofthe}pinnule ambulacra.

Ends

ofthe basal rays^{visible as} rliondjie tul)erclesinthe angles^of the calyx,butnot projectingabovethe general surface^ofthe_radials; radials rather prominent, nearly four times as broad as long, gently concave anteriorly; ⁱBrj about^twice

and

one-half asbroad_{as long,} the _straight lateraledgesin ajiposition^{; i}Br, _{(axillary)rhoml)ic,}al)outtwiceasbroad as long, the lateral edges about one-half as long ^as those of tlie i Br^;

II

Br

_2, inthe typedeveloped on^theright side ofthreeofthei

Br

_series,

on

both sides of one of the ⁱ

Br

_series, but absent from the fifth i

Br

series. Division ^series

and

firsttwobrachials exteriorly with auniformly produced

narrow

border,

by which

they are ^{in lateral}apposition,though they arenotlaterally flattened.

Arms

15 in

number

_(in tlie type) about 55

mm.

long; brachials in general ^{as in} P. macronema, ^l)ut sharjily rounded _dorsally in the distal halfof the

arm

instead of sharply cariuate, the long overlapping spines ofthat_speciesbeingrepresentedby insignificanttubercles onthe

median

part^of thedistaledge ^of each _joint. Syzygies occur between the third

and

fourth brachials, again between the twelfth

and

thirteenth or thirteenth

and

fourteentli,

and

distally at intervals of five toseven(usually sixor seven) oblique musculararticulations.

Pj⁸

mm.

long, stiff, ratliersmall, with nine_joints, the first not _quite solong^asbroad, thesecond _{slightly longer} than _broad, the third twice aslong^asitsproximaldiameter, theremaindergreatly elongated,except fortheminute terminal _joint; Pj ¹²

mm.

_long,

much

stouter than Pj, withnine_joints,similarin proi)ortion tothoseofPj^; Pg the longest on thearm, ¹³

mm.

or 14

mm.

_long, with eleven joints, of similar propor- tions tothose ofthe

two

_{precedingpinnules;} P4 ¹¹nun.long (intermedi- ate inlengthbetween Pj

and

_P2),witheleven or twelve joints, the first twice as l)road as long, the second _squarisli, the following gradually increasingⁱⁿlength,

becoming

greatlyelongateddistally; succeedingpin- nules similartoaboutthemiddleofthearm, then

becoming more

slender, slightly^lessstiff,

and

_decreasing in length distally to about 9

mm.

Pj

is occasionally absent,ⁱⁿ whichcase_P.^ is

much

smallerthanusual.

Color(in spirits).

—

Dull purple.

Type locality.

—

Turtle

Bay

ancliorage, north coast of Dirk

Hartog

Island, westAustralia; ⁷fathoms.

Rt'markft.

—

Pfitomrtra dorcadis is very easily distinguished from /'.

macronema

ofthe eastern coastofAustralia by ^the very long ^cirri which are

much

stouter_l)asally, the proportionately

much

_{greaterlength}of the lower_pinnuleswhichare longer than, instead ofshorter than, thedistal,

and

esi)eciallyby^the large^sizeof_P.^

and

the elongation ^of the _joints in allthe pinnules, these never l)eingso long^aswide in/'.macronema, even distally.

The

absence; ofdorsal carination

and

of oviTlajiping sj>ines on the brachials _gives the

arms

a

somewhat

(Htferent appearance. ^Its remarkal)ly robust aspect difterentiates it from P.

macronema

in about the

same

degree that thatspecies^isdifl'erentiatedfrom P. trichopoda^anil P.pulcherrima^ofthe Philippine^Islands.

Clarh

— _Two New

Australian Crinoids.

41

Tlie type ^of P.

macronema was

taken at

King

George's

Haven,

ⁱⁿ southwest Australia, while all the very

numerous

_specimens I have

examined

arefrom the eastern_coast, mostly from^PortJacksonorSydney;

thereisthereforeapossibilitythatthe presentspecies willturn out to be the truemacronema, ⁱⁿwhichcase the form from

Sydney

^would require a

new name and

_mightappropriatelybe

known

asPtilometra^miilleri.

Oligometra

^studeri sp. nov.

Type.

—

Cat.No._{2,9(54(part), Konigliche}Zoologisclies

Museum,

^Berlin.

Centro-dorsal thin, discoidal, the bare polar area flat; cirrus sockets arranged ^inasinglemarginal ^row.

Cirri xii, Ki-lS, 7

mm.

long;^firstjointvery short, the following grad- ually increasing ⁱⁿ length ^to the sixth or seventh, whicli, with the remainder, ^is squarish; on the third or fourth a low transverse _ridge, subterminalin position, ^is developed; ^this gradually moves, ^{in three or} four_{joints, to} a

median

position, at the

same

time _{gaining slightly} in height; distally this ridge progressively decreases ⁱⁿ width,

and

on the lastfour_jointsbefore thepenultimate becomes a low

median

_si)ine.

The

ridgesonall the_jointsappear ^as low _spines in lateral view. Opposing spine

median

in_iiosition, arising from the entire dorsal surface of the pemiltimate joint, in height equal ^{to al)out half} the diameter of that joint,

much

_longerthanthe short spines

on

the preceding joints; termi- nalclawratherstout, slightlylongerthan thepenultimatejoint,abruptly curved_basally, but

becoming more

nearly straightdistally.

Ends

ofthe basal raysnotvisible; radialsconcealedinthe

median

_line, butvisible in the angles ^of the calyx;,i Brj oblong, short, about four timesasbroad_{as long,} thelateraledgesstraight; i

Br

2 (axillary)broadly pentagonal, almosttriangular, abouttwiceas ])road as long; synarthrial tubercles _slightlydeveloped.

Arms

10, 45

mm.

_long; firsttwo brachialswedge-shaped, slightlyover twiceasbroad asthe exterior length, the^firstinteriorlyunited for rather

more

thantheproximalhalf, diverging^at

an

obtuse angledistally^; third

and

fourth brachials _(syzygialpair) slightlylongerinteriorlythanexteri- orly, abouttwiceasbroadasthe

median

_length; following three brachials oblong, about three times as broad as long, then

becoming

obliquely wedge-shaped,

and

after the twelfth triangular, slightly broader than long,

and

in theterininal part^ofthe

arm

wedge-shaped, about^aslong^as broad. After the tenth tiie brachials develop rather prominent

and

slightly overlapi^ing ^distal ends, but this character gradually ^dies

away

afteraboutthemiddleofthe arms. Syzygies occurbetweenthe third

and

fourth_brachials, again l^etween the ninth

and

tenth,

and

fourteenth and fifteenth (theformersometimes_omitted),

and

distally at intervals offour toseven (usually ^five) obliquemuscular articulations.

Pj about^4.5

mm.

long, slender, evenly tapering

and

_becoming flagel- late inthe distal portion,with about sixteen _joints, the first two rather over twiceasbroad _{as long,}the third nearly^aslong^asbroad, the^follow- ing gradually increasing ⁱⁿ length, being about ^{twice as} long ^as broad

42

Clark

— _{Two New}

Australian Crinoids.

diHtally^; I\ (>

mm.

_long,stouter

and

stiffer than _{Pj, being,} in _fact,the largest

and

longest pinnule

on

the arm, with about eighteen joints,the first two approximately ^{twice as l)roa(l} as long, the third squarish, the remaindera])out halfagain^as long^asbroad; ^thepinnule ^is smootli, the joints being without lateral processes or everted ends; Pg ³

mm.

long, small

and

weak, nearlyas large basally^asPj, but_tapering

more

_rapidly, with tliirteen joints, thefirstshort, the following increasing ⁱⁿ length ^to the _fourth,

which

^issquarish,

and

further increasing^toa length^of about twice the breadth in the terminal portion; following pinnules similar, sf)on l)ec(>ming

more

slender

and

gradually increasing ⁱⁿ length; ^distal pinnules very slender

and

hair-like, al)out 7

mm.

long,withtwenty-three joints, thetir.<tshort

and

crescentic,thesecond _nearly as long as l>road, slightly ^less in diameter _anteriorly than posteriorly,the third squarish, the remainder abouthalf again ^as long ^as broad,

becoming

^{about twice}

aslong^asbroadinthedistal portion.

Color (in sjjirits).

—

Brownish-purple, ^{the cirri}

and

dorsal surface lighter.

Ti/pc locality.

—

Dirk

Hartog

Island, westAustralia; ⁷fathoms.

JiCmarks.

—

This

new

^formisreadilydistingxnsliable from theten_previ- ously describedspecies ofthegenus; the elongatePj ^of0. hich'Ds, as well asthetwodorsal processes

on

itscirrus joints, the very

numerous

cirrus joints of 0. graciltcirra, the short stout cirrus joints of 0.pinniformis, thesingledorsal spine on the few stout cirrus joints of 0. caribbea, the strong imbrication ^of the brachials of 0. imbricata,

and

the spines or lateral processes on the proximal pinnules^of 0. yracilicirra, 0.carpen- teri, O.japonica, 0. piilchella

and

0.strripinna separate

them

at once.

The

_{elongate proximal} pinnules described ^{in 0.} adconx

would

^serve to ditlerentiateit, ifadco)ueshouldbe

shown

to really belong ^{to the} genus

Oligovii'tra.

Oligomc'tra studeri^is

most

closely related tothegroupof species typified

by

^0. serripinna.