MUSEUM OF COMPARATIVE ZOOLOGY. 271 



Ophiobyrsa Perrieri sp. nov. 



Plate II. Figs. 4-6. 



Special Marks. — Skin of disk naked, except clumps of short spines over 

 the radial shields. No spines on upper side of arms. 



Description of an Individual. — Diameter of disk 22 mm. Length of arm 

 270 mm. "Width of arm close to disk 4 mm. The mouth-angles, which are 

 covered with thick skin, have a few short spiniform papillae at the apex, ar- 

 ranged chiefly on the jaw-plate. Mouth-shields and other plates about the 

 mouth quite obscured by thick skin. Top of arm covered also by a very thick, 

 tough skin, but destitute of anything like upper arm-plates, except a certain 

 amount of thin lime-crust, underlying it. Under arm-plates swollen, rounded, 

 about as long as broad, and broader without than within. They are obscured 

 by the overlying skin. Side arm-plates like little flaps or pads inclining out- 

 ward. Disk rounded and wrinkled, covered by a thick skin which is naked 

 except over the radial shields where are clusters of very short, blunt spines. 

 Six equal, short, blunt arm-spines, not as long as a joint; when stripped of 

 the thick covering skin, they are rough and translucent. Tentacles large and 

 simple. No tentacle-scales. Color in alcohol, light yellowish brown. 



Bartlett, 3.3 m. S. E. by E. £ E. from Santiago de Cuba Light, 288 fathoms, 

 1 specimen. 



Ophiobyrsa serpens sp. nov. 



Plato VIII. Figs. 117-119. 



Special Marks. — Three short, glassy, slightly thorny arm-spines covered by 

 thick skin. Mouth-angle long and bearing a line of minute papilla; on either 

 side. 



Description of an Individual. — Diameter of disk 16 mm. Length of arm 

 (from another specimen) above 140 mm. Width of ami near disk 2.8 nmi. 

 On either side of the inner part of each month-angle ifl a line of about five 

 minute papillae covered by thick skin. Five small, spine-like teeth, of which 

 the uppermost are longest. A thick skin hides mouth-shields, side mouth- 

 shields, and under arm-plates. Side arm-plates project like little flaps. Disk 

 covered by a naked, wrinkled skin; along its margin runs a row of minute 

 peg-like spines, of which there is also a radiating row over the place of each 

 radial shield. Genital openings large and extending from the region of tin- 

 mouth-shield to margin of disk. Three short, glassy, slightly thorny arm- 

 spines, of which the lowest is longest and about as long as a joint; they are 

 covered by skin. No tentacle-scales. Color in alcohol, above, umber varie- 

 gated with yellowish brown; below, similar but lighter. 



Station 278, 69 fathoms, 2 specimens. 



O. serpens differs from 0. Psmtri in haying three arm-spines instead of tiv< ; 

 and in longer mouth-angles with minute papillae. The fact that it ptOB 



