264 BULLETIN OF THE 



without, and by a rounded angle or a deep curve within. Disk thick and 

 rising well above the arms, with a very deep constriction and radiating furrow 

 in each interbrachial space. The surface between the furrow and the radial 

 shield is occupied on either side by four large curved plates running diago- 

 nally inwards. The central disk is covered by coarse, irregular plates, similar 

 to those of the lower interbrachial spaces. All the upper surface except the 

 radial shields is sparsely set with smooth stumps. Radial shields large and 

 only a little sunken ; joined, except at their inner ends, which are separated 

 by a scale ; they are rounded without, pointed within ; length to breadth, 

 3.5 : 1.4. Genital openings reaching from the mouth-shield nearly to margin 

 of disk. Five flattened glassy arm-spines which are slightly thorny on their 

 edges ; the upper one is much the longest, and may equal three or four joints, 

 thence they decrease to the lowest, which is about the length of a joint. On 

 the first tentacle-pore are three erect, thickened tentacle-scales ; on the other 

 pores there is but a single thickened scale. Color in alcohol, pale straw. 



Variations. — There sometimes are as many as six scales on the first tentacle- 

 pore; and a small group of papillae at outer corner of mouth-slit. The great- 

 est number of arm-spines observed was six. It differs from 0. chelys in having 

 larger radial shields, which are joined and scarcely sunken (not at all in the 

 young), in having three or more scales on the first tentacle-pore, and in more 

 rounded under arm-plates. Most of the specimens mentioned under O. chelys 

 (Bull. Mus. Comp. Zool., V. 7, p. 153, and 9, p. 231), as brought by the first 

 " Blake " expedition, belong under this species, although one of them had seven 

 spines. I am satisfied that the deep furrows in the disk are natural to the 

 animal, and are not the result of contraction. 



Station 124, Santa Cruz, 580 fathoms. Station 131, Santa Cruz, 580 fath- 

 oms. Station 175, Dominica, 608 fathoms. Station 190, Dominica, 542 fathoms. 

 Station 204, Martinique, 476 fathoms. Station 205, Martinique, 334 fathoms. 

 Station 211, Martinique, 357 fathoms. Station 214, Martinique, 476 fath- 

 oms. Station 222, St. Lucia, 422 fathoms. Station 227, St. Vincent, 573 

 fathoms. Station 266, Grenada, 461 fathoms. Station 288, Barbados, 399 

 fathoms. 



Ophiomitra exigua? Ltm. 



Station 100, off Morro Light, 250-400 fathoms. Station 270, St. Vincent, 75 

 fathoms. Station 296, Barbados, 84 fathoms. 



Ophiomitra valida Ltm. 



Station 119, 18° 12' N., 64° 55' W., 1105 fat Ik mis. Stat inn l. r >(',. Montscrmt, 

 88 fathom*. Station 167, Montserrat, ISO fathoms. Station 171, Guade- 

 loupe, 183 fathoms Station 175 (young), Dominica, 611 fathoms. Station 

 193, Martinique, 169 fathoms. Station 816, Si Lucia, 154 fathoms. Station 

 218, St. Lucia, 164 fathoms Station 884, St. Vincent, 114 fathoms. Sta- 



