SIX NEW EAST INDIAN CRINOIDS BELONGING TO THE FAMILY CHARITOMETRIDiE.

PROCEEDINGS

_OFTHE

/?&

BIOLOGICAL SOCIETY OF WASHINGTON _/£ /CS^

SIX NEW EAST INDIAN CRINOIDS BELONGING TO THE FAMILY CHARITOMETRIDiE.

BY AUSTIN

H.

CLARK.

In

an

earlier

paper

^{in this}

volume (pp. 17-28)

^I described

seventeen new

crinoids

belonging

^to the families

Comasterida?

and Zygometridse which had been

discovered in the

East

Indies

by

the

Dutch _steamship

_Siboga.

The

_present

_paper

deals

with

the

new

_species of

Charitometrida'

in the

same

collection.

Preliminary

descriptions ^ofthe

new forms

in the

remaining

families will he

found

in the

current volumes

of the

"Notes from

the

Leyden Museum,"

^the

^"

Zoologischer

Anzeiger," and

the

"Annals and Magazine

^of

Natural History."

Family CHARITOMP:TRIDjE.

Pachylometra

^crassa sp. nov.

This form ^is nearest to P._flexilis, but itpossesses stouter^cirriwhich have ratherprominent ^dorsal processes distally,

and

the

arm

bases are

much

smoother, ^{theaxillaries}

and

corresponding ^ossicles beingwithout the characteristicmedian tuberclesand rounded_{posteriorprocesses.}

The

centrodorsal is very large,truncated _conical, the sides

making

^a rather small angle with each other, 9

mm.

indiameteratthe_{base, 5}

mm.

across the irregularly convex dorsal _pole,

and

.5

mm.

_{high; the} cirrus sockets arearranged ^{in ten} columns, usually threeto acolumn, ^{the col-}

umns

_{beingclosely crowded} interradially, slightlyseparated radially.

The

cirri are about xxv, 18-22 (usually20), 32

mm.

long, stout and short segmented; ^{the first}segment ^isshort,and the following gradually increase in length sothat the sixth

and

following are nearly^as long ^as broad, those ⁱⁿthe outerthird ofthe cirri being slightly shorter again;

on the seventh_{a slight} broad subterminal dorsal

hump ^makes

^itsappear- ancewhich slowly increases ⁱⁿ height ^so that the terminal nine possess a prominent broad ^blunt andwellrounded subterminal tubercle which

13—Peoc.Biol. Soc.Wash.,Vol.

XXV,

1912. (77)

78 Clark

—

Six

New

East Indian Crinoids.

becomes

more

_pointed onthe last two or three before tlie penultimate;

the opposingspine^issmall, subterminal, resembling the tubercleon the precedingsegment, butarising from a

much

smallerbase.

The

radials

and

theends ofthebasal rays are concealed; the iBr, are very short, broadly V-shaped, sometimes ^{concealed in the}

median

line sothat only the ^lateralportions arevisible; the dorsal surfaceis

more

or less irregular; the axillaries are short

and

broad, nearly three times ^as broad _{as long,} rhombic,^{the lateral} angles truncated sothat the lateral sidesare nearly or quite^aslong^asthoseoftheiBn.

The arms

are ten oreleven in

number,

^{about 180}

mm.

_{long; the}first

two brachials areabout_equal in _size,slightly wedge-shaped (more pro- nouncedly^so on the second), about threetimes asbroad asthe

median

length; the synarthrial tubercles are scarcely

marked;

the brachialshave slightlyproduced^distaledges

and

a

more

orlessswollen dorsalsurface.

Type locality.—"Siboga"^StationNo. 259.

Pachylometra

^Melius sj>. nov.

This

new

form isnearest P. septentrionalis ofJapan, ^{butit is of}

more

delicate buildwith

much more

slendercirri

and

with the dorsal surface ofthedivision series

and arm

bases stronglyconvex

and

_perfectlysmooth without any ^{trace of}

median

carination oroftubercles.

The

centrodorsal is of moderate_size, flattened hemispherical or thick truncated conical, ^6'

mm.

in diameter atthe_{base, 3}

mm.

^{across the flat}

dorsal pole

and

4

mm.

_{high; the}cirrussockets arearranged ⁱⁿten equally separated columnsoftwoor three each.

The

cirriareabout xxv,23,about28

mm.

long; the^firstsegment^issitort, the following gradually increasing ⁱⁿlength^to thefifth

and

sixth which are the_longest, between onethird

and

onehalfagain ^aslong^as broad;

the followingsegmentsvery slowly decreaseⁱⁿlength so that thoseⁱⁿthe distal third of thecirri areabout as long ^as the distaldiameter; ⁱⁿthe distal third ofthecirri the

median

_portionofthedistal dorsaledge^ofthe segments ^is

somewhat

_swollen,this onthelastfiveorsix before the penul- timatebecoming^{a blunt}subterminal dorsal tubercle; theopposingspine

is prominent, short,sharp, terminal, directed obliquely forward.

The

ends ofthe basal rays are^visibleas large rhombictuberclesin the angles^ofthe calyx; the ^radialsare_entirelyconcealed; the

iBn

^arevery short, broadlyV-shaped with^the proximal

and

distal edges parallel^; the lateral thirdsofthe proximal

and

distaledges areslightly produced; the axillaries are very short, nearly or quite three times ^as broad _{as long,} rhombic in shape ^with concave sides

and

truncated lateral angles, the lateral edges being^aslong ^asthoseof the

iBn;

^thelateraledges

and

all

but the

median

_portionoftheproximal edgeare very slightly produced^; the synarthrial tubercles arelow

and

broad, scarcely evident.

The

basalcontour oftheanimal isbroadly rounded,exactly^like that ofP. septentrionalis.

The

twenty-six

arms

of the type are 125

mm.

long; there are seven

iiBr4(3

+

4)

and

three

nBr

2 series; the in

Br

series are 2, internally

79

developed excepl ^for one which ^i- external by ^{the side of} an internal miBrseries.

Typelocality.

— "Siboga"

station No. 254.

Pachylometra

fragilis sp. nov.

The

centrodorsal is low, flattened hemispherical, ⁷ nun.in basal diam- eter and 3

mm.

_{high; the} cirrus sockets are closelycrowded, ⁱⁿ twoor three _irregular rows and approximately ^fifteen columns, ^{three in each} radial area: the cirrus sockets touch theproximal ^{border of}the centro- dorsal.

The

cirri are about xxx, L7-18, 30 nun. to 35

mm.

_{long, moderately}

-lender; the first four segments are short, the fifth is halfagain ^aslong as broad; ^the sixth-eighth ^are the_longest, twice as long as broad; the followingslowly decreaseⁱⁿ length becoming about ^as long^as broad dis- tallyand then increase again ^sothatthepenultimate and antepenultimate areabouttwiceaslong ^asbroad; the^earlier longersegments haveslightly prominent ^ends, and theshorter distal segments have ^{the distal dorsal} margin slightlyswollen.

The

subradial clefts are deep, but _very narrow; ^theends ofthebasal raysare visible as large

and

_prominent

rhombic

areasinthe angles^ofthe calyx; the ^radials are veryshort, strongly curved, with ^a lowbroad ob- scure median _tubercle; the r B.nare extremelyshort,band-like, withan obscurelow

median

tubercle; they areproduced inward toward^{the center} ofthe calyx^sothattheir sharplyflattened lateraledgesalmostmeet, being separated only by^a narrowly V-shaped ^cleft running ^{to the}edge ^ofthe inner edge^ofthe synarthrialjoint face; thoughthe dorsal surface ofthe segment^iswell rounded the distance fromthe centralcanaltothe

median

part of the dorsal edge ^{is not so}great ^as the distance fromthe central canal to the inner angle; counting ^{the entire}

median

_length ofthe_joint facethe broadest portion ^isfound to be scarcely

more

than one third of the distancefrom the dorsaledge^tothe innerangle; ^theossicleissharply

"wall-sided" from its widest point inward; ^{the axillaries are} low, rhombic, with the lateral angles truncated ^sothat the lateral edges are about as long ^as the lateral edges ^ofthe

iBn,

^{twice as broad as} long;

there is an obscure well rounded

median

carination; the^distal angle ^is produced, but broad; the dorsal surface ^is rather strongly convex; ^the lower portions ^of theaxillariesare stronglyproduced inward so that, like the ⁱ Bri, the innersidesarereduced almost _{to apices}which almost meet the similarinnerends ofthe other axillaries; fromthis central point the inner face of the axillaries slopes

away

almost horizontally ^so that the inner lace- of the axillaries, together with the division series, form the platform upon which ^{the visceral}

mass

rests; the sides of theinnerhalf of the axillaries are sharply "wall-sided"; ^the

nBr

^{series are similar}

to thi' iI>r series, hut rapidly decrease ⁱⁿdorsoventral width; they are sharplyflattened laterally for

somewhat more

than their innerhalf; the

firsttwobrachialsareflattened laterally^fortheir entire innerside and ^the third and fourthare flattenedon the inner portion ^ofthe innerside.

80

Clark

—

Six

New

East

Indian

Crinoids.

Piis 9

mm.

or 10

mm.

_long, slender

and

evenly tapering, with from twenty-six ^to thirty-one segments ^{all of} which are

much

broader than long; P2 ^is similar, very slightly stouter, of the

same

length or very slightly longer, with twenty-five segments ^of which the outermost are about as long ^as broad; Pais ¹¹

mm.

_{long with twenty-two segments,}

resembling^P2, butwith thesegments ^{inthe distalhalf} about as long ^as broad; ^{P4is 11}

mm.

_{long with} twenty segments which

become

aboutas long^as broad onthefifth orsixth

and

_{slightlylonger} than broadtermi- nally; P5is 9

mm.

_{long with} fifteen segments, most ofwhich are about as long ^asbroad; Pgis 8

mm.

long with fourteen segments; ^{P9 is7}

mm.

long with ^thirteen segments; ^{in the} genital pinnules the third-seventh segments ^are just perceptibly broader than those ifollowing; the distal pinnules are veryslender, 10

mm.

longwith twenty segments.

Type locality.—"

Siboga" _Station No. 1.6(5.

Glyptometra

^timorensis sp. nov.

This

new

_species isnearest to G. lata of southernJapan, but the^cirri areshorterandslightly stouter, with shorter segments,

and

the

ornamen-

tation ofthe ossiclesofthe iBrseries

and

of the proximal ^{brachials is}

much more

smooth andregular; there^is none ofthe coarsely tubercular rugositycharacteristic of G. lata.

The

centrodorsal is verythick discojdal, the sides sloping slightly in- ward, ^6.5

mm.

in diameteratthe baseand^:!

mm.

high^; thecirrussockets are arranged ^{in ten} columns of two each, the columns _{being closely} crowdedagainsteach otherand showing nodifferentiation into pairs.

The

cirri are xx, 17-20, 20

mm.

to 25

mm.

long, stout; the firstseg-

ment

isvery short,the following gradually increasing ⁱⁿlength^to about the seventh, which, with the following, ^is about twice as broad as the median _length,or,in the_{longest cirri,} halfagain ^as broadasthemedian length; the dorsal _{profile of}thesegmentsbeyond^theseventh or eighth ^is convex,becominggradually

more

_stronglysotoward theend ofthecirri.

The

ends ofthe basal rays are^{visible asflat}triangular or irregularareas in the angles ^of the calyx; the ^radials are _entirely concealed or are slightly visible as small irregular tubercles orflat irregular areas inthe angles ^of the calyx; the ¹

Bn

^are short, broadly chevron-shaped, ^the proximal and ^{distal borders} parallel, about fourtimesas broadas long;

the proximal edge ^is produced ^{into a}thin border overlapping

and

con- cealing the proximal portion ^of the centrodorsal, though ^{flush with its} general surface; the border of this produced proximal edge ^{is usually} irregularlyscalloped or bears a few lowcoarse _teeth, though ^it

may

^be

nearly plain; ^it sometimes bears a few low_tubercles; it

may

be evenly curved, becoming ^horizontal justover the ends of the basal _rays, or it

may

^be regularlycurved in its lateral thirds but _nearlystraight in ^its

median

_third; the middleof the dorsal surfaceofthe1

Bn

^isoccupied by a _large prominent broadly oval ^well rounded tubercle; the axillaries arebroadly rhombic^{with the lateral}angles truncated so thatthe lateral edges arefrom onehalf to twothirds the length ^ofthesides oftheiBn,

Clarl

—

Six

New

East Indian Crinoids.

two and one halftimes as broad _{as Long,} in the median line nearly twice as long ^{as the i 1 i-1;} the_center, excepl ^at the anterior_angle, isoccupied by ^{a tubercle} which ^is

more

elongated dorsoventrally than ^that on the

i E$n and, though as high, ^less prominent ^{as itrises}

much

^less_abruptly;

thelateral edges^ofthe ⁱ Bri and iI'.r-jareturned outward,^{but not}nearlj so stronglyas ^isthecasein G._lateralis; the lateral thirds oftin¹proximal edgeof the axillaries and the corresponding portionsof the distal edge^of

i

Bn

are also turned

upward

^{to the}

same

_heightas thelateral edges; the eversion ofthe latter is most

marked

just,over theendsofthebasalrays and gradually decreases anteriorly^tothedistal corner ofthe lateral edge ofthe _axillary; it is continued thence along the sides of the first four brachials; ^the inner lateraledges ^ofthe first live brachialsare_similarly modified.

The

ten

arms

_{are, in}the type, 105

mm.

_long.

Type locality.— ^'Siboga" ^Station No. 21)7.

Strotometra priamus

sp. nov.

The

centrodorsal isvery lowhemispherical, almost _discoidal, 1.5

mm.

to 2

mm.

ⁱⁿdiameter; the^cirrussockets arearranged ⁱⁿoneand _{a partial} second marginalrow, alternating and_closelycrowded.

The

^cirri are xvn, 11-12, S

mm.

to 11

mm.

long, slender, with elon- gated segments; ^{the first} segment ^isveryshort, dorsally

expanded

^into

a rounded knob-like process; thesecond is not quite ^solong ^asbroad;

thethird istwiceaslong^asthe

median

diameter; the remainder_{are very} slightly shorter, becoming ^atriflelonger again, about two and one half times as long ^as broad, on the antepenultimate

and

penultimate; the penultimate ^{isless in lateral}diameter thanthe preceding; the third

and

following^are moderatelyconstricted _centrallywith prominent^distalends, thisfeaturegradually decreasingdistally; there are no dorsal processes;

the opposing spine ^is prominent,terminal, directed obliquely forward, the proximal profile convex and the distal concave; the base occupies onlyslightly

more

than one third ofthe dorsal surfaceofthe penultimate segment.

The

ends ofthebasal raysare visible as small hut prominent^tubercles

in theangles^ofthe calyx; the radials areconcealed by the centrodorsal:

the i

Bn

are short, about four times asbroad as longⁱⁿ the median _line;

the proximal ^{border is}slightly convex, usually becomingstraight ⁱⁿ the lateral quarters; the^lateraledges^ofeach ^t

Bn make

^aconsiderable angle with each _other, but are in close apposition with those ^{of the} adjacent

iBr,^; they are turnedoutward

and

_produced as in Gly/itometra lateralis;

the distaledge ^is sometimesobscurely scalloped ⁱⁿ the lateral thirds, and

isslightlyconcavecentrally forthe _{receipt of}a rounded posteriorprocess from the _axillary; the axillaries are exceedingly short, aboul two and one halftimes asbroadas long: their lateraledges form acontinuousline with those oftheI

Bn ^and

^{areabout half as}long ^asthe _latter; they are similarly turned outward and _produced, ^this feature continuinginward

82

Clark

—

Six

New

East

Indian

Crinoids.

along the proximal ^border about as far as the

median

third; thedistal edges areslightlyeverted.

The

ten

arms

are40

mm.

long; the^firstbracbial hasthe proximal

and

distal edges parallel; ^{it is} in close apposition with its neighbors both internally

and

externally; the proximal edge ^is slightly everted; the outeredge ^{is turned} outward and produced, ^like the outer edges ^ofthe preceding^ossicles; theinneredge^issimilarly,though^less,turnedoutward

and

_produced; the synarthrial tubercles are small and well rounded, but rather prominent; ^the second brachial is similar to the _first, but about twice as long exteriorly ^as interiorly; the third

and

fourth (the ^first syzygial pair) are togetherroughlyoblong, about two

and

onehalftimes asbroadas long, tbeir lateraledges being modified ^{as in} thetwo _preced- ing; the following three brachials arewedge-shaped, about^twiceasbroad as the

maximum

_length, with the dorsal surface convex and the distal edge^thereforeprominent; ^afterthe tenth the brachials

become

_triangu-

lar,aboutas long^asbroad,^latervery obliquelywedge-shaped

and

toward theend^ofthe

arms

twice aslong^asbroad.

Pi ^iso

mm.

long with thirty-five segments, very slender

and

delicate, resembling, except ^for the absence of the enlargement ^{of the first} two segments, ^{Pi in} Calometra; the earliersegments ^are broaderthan _long, the seventh or eighth

and

_following aboutaslong^asbroad; Ps^is6

mm.

long with eighteensegments ^ofwhich thesixth-eleventh are greatly pro- ducedventrally forming^aroofover the gonads, which arealsoprotected by^a heavy ventral plating; the terminal sevensegments are very small

and

_delicate; Pa^issimilar, 4.5

mm.

long with fourteen segments,^ofwhich the sixth-tenth are greatly

expanded

^{; P4is4}

mm.

long with thirteen seg- ments, ^the fifth-ninthexpanded; ^{P5 is 3}

mm.

long with ten segments, none of which are expanded; ^{the distal} pinnules are ⁵

mm.

_{long with}

eleven ortwelve segments.

Type locality—

"Siboga"

^{StationNo. 266.}

Strotometra

ornatissimus sp.

now

The

centrodorsalisflattened hemispherical^2.5

mm.

inproximal diam-

eter,with the dorsal poleslightlyconvex; ^thecirrussockets arearranged inone

and

a_partialsecond_closelycrowded

and

_{irregularmarginal} row.

The

cirri are about xv(there are twenty-twocirrus sockets, but

some

of

them

arenotoffullsize); the longest

stump

^{is 4.5}

mm.

to the distal dorsaledge^ofthefifthsegment; ^thefirstsegment^isabouttwiceasbroad as long, thesecond aboutaslong ^asthe

median

_{diameter, centrally} con- stricted,the third about twiceaslong ^asthe

median

diameter _centrally constricted with thedistal

end

_{especiallyprominent}as in the second, the fourth about threetimes aslong ^asthe

median

diameter, similar ^tothe third, thefifth similar to the fourth but _{not quite} so

much

constricted centrallyand hence appearing slightly broaderin lateral view.

The

radials are just visible beyond ^the edge ^of the centrodorsal; the

1

Bn

^areshort,aboutfour timesasbroadasthe

median

length,the proxi-

mal

border produced ^{into a thin} straight margin, ^{the lateral borders}

Clark

New

Indian

r

slightly

more

produced and ^turned outward; theaxil laries form a broad inverted

"V";

^the lateral edges, which are halfagain ^as long ^asthose ofthe ^II>n are, like them, ^turnedoutward and are straighl or heartwo or three broad scallops; the lateral thirds of the proximal ^{border are} produced and extended

downward

over the distalborderofthei

Bn

with a scalloped^ortubercularedge which ^is nearly parallel to thecorrespond- ingdistal face; thedistal sidesof the axillaries are plainand unmodified.

The

ten arms areabout 40

mm.

Ions; the^firstbrachial has the proxi- mal and distaledgesparallel,the outeredgeslightlyproduced

and

_faintly

scalloped, the inner edges ⁱⁿ apposition, in their distal half evertedand scalloped; ^a similar distance of the inner portion ^of the distal edge ^is similarly everted and _scalloped,

and

the internal distalangle ^isrounded, so that the innerdistal angle ^is produced ^{into a}rounded thin scalloped process; the proximal and ^distal borders, otherthan abovedescribed, are unmodified; ^the second brachial is about as large as the first, slightly wedge-shaped; ^thedistaledge ^{is everted}

and

stands out _{at right}angles to the dorsoventral axis of the

arm

as an

enormous

thin rounded or fan-shaped ^crest with a rounded or broadly scalloped edge, sometimes divided in the middle, which

may

^{reach 1.5}

mm.

in height, or three ^or four times the greater (outer) length ^of the ossicle; the proximal ^outer corner of theossicle is slightly produced ^{over the distal} outer cornerof the first brachial,

and

isscallopedor slightly tuberculated; theproduced inner distal angles ^of the first brachials reach as far as thebase ofthe distal crest onthe second; thethird brachial (thehypozygal ^{ofthe first} syzygial pair) ^isoblong, unmodified, veryshort,^fiveor sixtimesasbroad aslong; the fourth brachial (the epizygal ^ofthefirstsyzygialpair)^isvery short,oblong, ^{little if} anylarger than the preceding brachial, butwith the distal border everted

and

_produced into an

enormous

crest similar to,

and

nearly or quiteas large as,thatonthesecond brachial; the^fifth brachial isslightly wedge-shaped^{with a crest}about half ashigh ^as that onthe preceding brachial

and more

_irregular; the sixthbrachial hasa strongly produced

and

thickeneddistal edgewhich ^iscoarsely scalloped;

the seventh brachial is slightly wedge-shaped, two ^to two

and

onehalf times as broadas long,unmodified, with the^distal edge slightlyproduced

and

_{finelyspinous;} afterthetenth or twelfth the brachials becometrian- gular, about as long^as broad, and afterfouror five

more

_{veryobliquely} wedge-shaped and longer than broad, ^less obliquely wedge-shaped and longerdistally^; the brachials beyond ^{thesixth are almost} smooth,^with onlyslightly produced and finelyspinous^distalends.

Typelocality.

— "Siboga"

Station No. 122.