354 A. JEJ. Verrill — North American Ophiuroidea. 



plates are smaller on the basal joints than farther out. They are 

 broader than long, with a concave emargination on the distal edge. 



The dorsal arm-plates are rather quadrant-shaped, with a broad 

 lobe on the distal edge, and with prominent lateral angles. Some 

 of the basal arm-plates are slightly in contact. Arm-spines ten, 

 rather stout, roughly serrulate, blunt, the rows not approximate 

 dorsally. The radial shields are larger, irregularly triangular, more 

 or less encroached upon by the disk-scales and granules. The disk- 

 scales are not large, all nearly equal, sparsely covered with short, 

 coarse, rough, capitate stumps. The interradial margins have a 

 small notch in dried specimens, but not larger scales. 



Oral shields small, pelecoidal, with an acute inner angle, and a 

 prominent convex outer end. Adorals about as large as the orals, 

 wide, lunate, the surface finely granulous in appearance. In younger 

 specimens the distal oral papillae form one irregular row of about 

 three or four around the pore. 



Common throughout the West Indies in 10 to 1105 fathoms (Blake 

 Expedition), 



OPHIOCAMAX Lym. Type, O. vitrealjjm. 



Ophiocamax Lym., Bull. Mus. Comp. Zool., vol. v, p. 156, 1878; Voy. Chal- 

 lenger, T, p. 309, 1883. 



This genus is closely allied to typical Ophiomitra. Like the latter 

 it has numerous tooth-papillse in an apical cluster, and a cluster of 

 distal oral papillae, even more numerous than in Ophiomitra. 



In the type-species there is also a sj)ecial small distal plate (pro- 

 cess of under arm-plate ?) which bears two or three small papillae 

 dii-ected proximally and serving as part of the papillae for the large 

 oral tentacle-pore. 



The basal tentacle-pores have three or four elongated, erect tenta- 

 cle-scales forming a sheath for the tentacles. Radial shields are 

 wide and in contact. Disk-scales, which are usually visible, bear 

 thorny spinules, but in the type species they are scarcely visible 

 and closely spinulose in the adult. 



The adoral shields are large and broad, situated in front of the 

 oral shields. 



Synoptical table of the sjyecies of Ophiocamax. 



A. — Typical. Dorsal arm-plates, at base of arm, not separated by 

 the side-plates. Rows of spines not approximate dorsally. 



