274 BULLETIN OF THE 



84-125 fathoms. Bartlett, 21° 23' 19" N., 82° 54' 42" W., 300 fathoms. San- 

 tiago de Cuba, 288 fathoms. Station 319, 32° 25' N., 77° 42' 30" "W., 262 

 fathoms. Station 320, 32° 33' 15" N., 77° 30' 10" W., 257 fathoms. 



Ophiomyxa serpentaria sp. nov. 



Plate Tin. Figs. 114-116. 



Special Marks. — Three short, tapering, blunt, translucent arm-spines en- 

 closed in skin-bags. Three small mouth-papillae on either side of the mouth- 

 angle, near its apex. Under and side arm-plates soldered together. No upper 

 arm-plates. Skin of disk without apparent scales and with only small radial 

 shields. 



Description of an Individual. — Diameter of disk 19 mm. Length of arm 

 50 mm. Width of arm near disk 3 mm. On either side of each mouth-angle, 

 near its apex, are three mouth-papillae, of the usual flattened form with saw- 

 like edge. The innermost one is largest; the two outer ones are smaller, and 

 more or less obscured by thick skin. Teeth similar to innermost mouth- 

 papilla. Mouth-shields and side mouth-shields wholly hidden by thick skin. 

 On removing the skin there are seen under arm-plates of elongated shape with 

 deep re-entering curves on their sides where are the tentacle-pores; they are 

 soldered together and with the side arm-plates, and have on their upper sur- 

 face four knobs for attachment to the arm-bones. Side arm-plates thick and 

 shapeless, extending to the upper surface of the arm. No upper arm-plates. 

 Disk covered by a smooth tough skin, which under the microscope is seen to 

 be full of httle, rounded, thin scattered scales. There is no marginal row of 

 plates; and the verj' small radial shields, which lie in the angle made by the 

 arm with the disk, have no bed of scales. Genital openings running from 

 mouth-shields rather more than half-way to margin of disk. Three arm-spines 

 about 1.7 mm. long, widely spaced and standing at a large angle with the arm; 

 their base is enclosed by thick skin, which being stripped off, they appear 

 cylindrical tapering, blunt, and translucent; under the microscope they are 

 slightly rough. Tentacles large and fleshy, but without scales. The articu- 

 lating faces of the arm-bones do not approach the Astropbyton form so much 

 as do those of other members of the genus, but come nearer the type of the 

 true Ophiurans. 



" Porcupine" Expedition, Station 54, between Faroe Islands and Hebrides, 

 363 fathoms, water 0°.3 Cent., 1 specimen. 



The under ann-plates are shaped somewhat like those of 0. vivipara, while 

 the di.sk-skin, almost without lime-scales, reminds one of 0. australis. Tin- 

 absence of upper arm-plates marks this new species aa the Northern corre- 

 spondent of the Antarctic O.vivipctra, which is plentiful; and it is therefore 

 singular that only one specimen of the Northern representative should thus far 

 have been found. 



