112 BULLETIN OF THE 
angular plates of the same character. Radial shields small, minutely tuber- 
cul^ .s, rounded triangular ; length to breadth 1.5 :.7 ; widely separated by 
a group of half a dozen plates, of which the outer ones are much wider than 
long. Two or three minute peg-like arm-spines situated in a notch low on 
the side arm-plate. Color in alcohol, pale gray. 
Station 236, 420—470 fathoms, 1 specimen. Station 33, 300 fathoms, 
(same species?) 1 specimen. 
Ophiomusium archaster Wrv. Tuom. MS. sp. nov. 
Plate II. Figs. 28, 29, 32. 
Special Marks. — Arms rather slender and tapering, cylindrical, or but 
slightly wavy. Upper and under arm-plates persisting nearly to end of arm, 
but no tentacles beyond third or fourth under plate. Genital opening bounded 
by small close-set papilla. Disk covered by thick skin, its upper surface occu- 
pied chiefly (and in half-grown specimens almost entirely) by radial shields 
and large primary plates, with small scales between. Arms even and cylin- 
drieal. Four minute rudimentary arm-spines. 
Description of an Individual (Station 323) — Diameter of disk 10 mm. 
Width of arm close to disk, without spines, 2.5 mm. Five mouth-papille 
on each side, short, pointed, closely joined, with one large, diamond-shaped, 
at angle of jaw. Mouth-shields broad heart-shaped, with. a peak within; 
length to breadth 1.3:1.5. Side mouth-shields long triangular, very broad 
without; tapering and curved inward, where they meet. First under arm- 
plate very small, triangular, with angle inward ; the three next bear ten- 
tacle-scales, and are three-sided, with lateral sides a little re-enteringly curved 
and outer side slightly curved; the rest are small, triangular, with outer 
side curved. Side arm-plates thick, slightly swollen, somewhat constricted 
within, meeting below throughout, and above beyond the third upper arm- 
plate. First two upper arm-plates rounded and much wider than those 
beyond, which are triangular, with an angle inward, lateral sides straight, 
outer edge much curved. Disk flat, covered with thick, minutely tuberculous 
plates and scales, Radial shields sunken, of irregular rhomboidal shape, with 
corners rounded ; length to breadth 1.7 : 1.3. Central primary plate smaller 
than the others, circular, sunken, separated by a double row of small circular 
scales from five large sunken, nearly round plates which surround it; the rest 
of the upper surface is covered with small rounded scales, with a larger one 
on the margin, Under surface covered with small rounded plates, irregularly 
disposed ; genital scales long and very narrow, on the free edge of which are 
fine, short, square papillz, corresponding to similar ones on the side arm-plates. 
One small rounded tentacle-scale, situated near inner angle of plate. Three 
or four minute, slender, rounded arm-spines standing low down on arm- 
plate; upper one longest. Color in alcohol, straw. 
Station 323, 1900 fathoms, 5 specimens, 
