110 BULLETIN OF THE 



but no tentacles beyond third or fourth under plate. Genital opening bounded 

 by small close-set papilla), 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-papillae 

 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 Avithin. 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 papilloe, as in Ophioglyplm. 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 i!nd of arm, 

 but no tentacles beyond third or fourth under plate. Genital opening bounded 

 by small close-set papilla). Disk thick. Side mouth-shields and under arm- 

 plates much swollen. Outer mouth-papilla; much larger than inner. Genital 

 papilla; large and bead-like. Six or seven small arm-spines. 



Description of an Individual (SUition 224). — Diameter of disk 12 mm. 



