110 BULLETIN OF THE 
but no tentacles beyond third or fourth under plate. Genital opening bounded 
by small close-set papille, which extend upward as a small arm-comb. Side 
mouth-shields small and short. Upper arm-plates comparatively large, some 
of the basal ones inclining to hexagonal. Three or four small arm-spines. 
Description of an Individual (Station 332).— Diameter of disk 11 mm. 
Length of arm 47 mm. Width of arm near the disk 2.5 mm. Mouth-papillo 
six on each side, forming a close line, and one larger one at apex of jaw. 
Mouth-frames long triangular, quite large. Mouth-shields rounded triangular, 
with an angle inward ; length to breadth 1.5 : 1.5. Side mouth-shields short 
triangular, touching by their narrow ends within. First under arm-plate 
circular, very small; the next three are furnished with tentacle-scales, and are 
three-sided, with an angle inward, and outer side curved; the others are 
smaller and roughly triangular, with an angle inward, and lateral sides curved. 
Side arm-plates thick, and meeting broadly below beyond the disk, but 
just touching above on the basal joints. Upper arm-plates long, diamond- 
shaped, except at base of arm, where the outer and inner angles are truncated. 
Genital scales very narrow, and so closely soldered to surrounding parts as to 
be hardly distinguishable. Near inner end of genital opening they bear a few 
square close-set papilla, as in Ophioglypha. Interbrachial space below covered 
by ten or a dozen circular plates of irregular outline, Upper surface of disk 
covered by long, rudely triangular, somewhat sunken radial shields, widely 
separated their entire length by two or three large and several minute rounded 
plates ; the interbrachial space covered by a large circular marginal plate, with 
various smaller ones within ; the central space within the radial shields by six 
rounded, sunken primary plates, separated by about three rows of small scales, 
The entire surface is microscopically tuberculous. Three or four small cylin- 
drical arm-spines, situated well up on the outer edge of the side arm-plate ; 
they stand out from the arm, and the two middle ones are largest. The 
second, third, and fourth under arm-plates have, near their inner end, small 
oval tentacle-scales, one to each pore. Color in alcohol, white. 
Station 83, 1650 fathoms, 2 specimens. Station 106, 1850 fathoms, 5 speci- 
mens. Station 299, 2160 fathoms, (same species?) 1 specimen. Station 332, 
2200 fathoms, 1 specimen. 
Ophiomusium corticosum sp. nov. 
Plate I. Figs. 19, 20. 
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 hounded 
by small close-set papilla. Disk thick. Side mouth-shields and under arm- 
plates much swollen. Outer mouth-papille much larger than inner. Genital 
papilla large and bead-like. Six or seven small arm-spines. 
Description of am Individual (Station 224). — Diameter of disk 12 mm. 
