A new unstalked Crinoid from the Philippine Islands

Vol. 33, pp.21-22 July24, 1920

PROCEEDINGS

OPTHE

BIOLOGICAL SOCIETY OF WASHINGTON

A NEW UNSTALKKD CRINOID FROM _THE

PHILIPPINE ISLANDS.

BY AUSTIN

^H.

CLARK.

In a

large collection of

comatulids

_recently

received

at

the

Museum

of

Comparative Zoology from the

Philippine Islands,

Dr. Hubert Lyman ^{Clark found two} specimens

^of

a new

_species

of Oligometrides related to

the Australian

0. adeonce

which he has requested me

to describe. It

may ^be

^called

Oligometrides bellona, sp. nov.

Description.

—

Centrodorsalthin, discoidal,the dorsal pole^flator slightly convex, about2.5

mm.

in diameter,studded withwellspaced

and

_evenly distributed granulartubercles; within the circle of cirri is a

more

or less complete ^{circle of}

empty

^{cirrus sockets each with a}

more

or less hemi- spherical

median

tubercleinthecenter.

Cirri

XXIV,

21-23, about ¹³

mm.

long; cirrus segmentssubequal, not quite^solong^asbroad;onthe third the proximal^borderisbroadly^thick- ened, ^this thickeningonthe fourth

and

_{followingbecoming} a high trans- verse ridgewith_{a sharp,}straight crestwhich onthesegments^intheouter half ofthe cirri becomes,

when

the segments^are viewed endwise, evenly convex, then gradually gable-like,

and

on the antepenultimate reduced toa _singlespine situated onthe proximal edge ^of the segment;

on some

of the middle

and

outer segments ^{of certain cirri}

midway

^{between the} proximaltransverse ridge

and

the distaledge^thereis a transverse

row

of minutetubercles representing the^distaltransverse ridgein 0. adeonce; these, however,^arenot alwayspresent,

and when

present are inconspicuous.

Division series broad, thin, in lateral contact, the borders narrowly flattenedagainst thoseofthe _platesoneither side

and

therefore_straight;

synarthrial tubercles veryprominent and sharp, slightlyproduced^; IIBr series2.

Arms

11 innumber, about100

mm.

long,resembling thoseof 0. adeonce.

2—

Proc. Biol. Soc. Wash.,Vol.33, 1920. (21)

>

22 Proceedings

of^the Biological Society of

Washington.

The

pinnules are essentially similar to thoseof 0. adeonce; Pi 13

mm.

long, rather _stout, stiff, tapering evenly from the base to the _tip,

com-

posed^{of fifteen}segments,^allbutthefirstofwhichare longerthan_broad, the outer being about twice as long as broad; P2 ^{similar to Pi,} 16

mm.

long, butproportionately stouter

and

_tapering

more

_gradually,

composed

of fifteenor sixteen segments,ofwhich thefirstisbroader than_long, the secondisaboutas long^asbroad,

and

the following^arelongerthan_broad, mostly about twice as long ^as broad;

P

3 similar to P2

and

of the

same

length or veryslightly shorter,

composed

^offourteen or fifteensegments;

P

4 similar to

P

3, 12

mm.

long withfourteensegments; followingpinnules shorter

and more

flexible, with shortersegments;

P

Bis 9

mm.

_long with twelve segments; ^distal pinnules slender, 13

mm.

_long with twenty-two segments.

Localities.

—

Southwest of Sorsogon Bay, Luzon. ^{Philippine Islands} 9-40 fathoms; cable repair ship "Rizal" _{(A. S.}

Day)

September, 1912 (the-type-specimen, Cat. No. 705

M.

C. Z.). Port Galera, Mindoro, April-June 1912;L.E. Griffin (Cat. No. 706

M.

C. _Z.).