OPHIUROIDEA OF THE BAHAMA EXPEDITION. 39 

 O. nuttingii Ver. sp. now 



O. rubescens (Koehl.) off Azores, 845 meters. 



;/ . ;/ . — Ofihiomitrella Ver. Dorsal arm-plates separated by 

 the side plates. Arm-spines slender, thorny, the basal 

 rows approximate dorsally. 



O. Icevipellh (Lym.) 



m. m. — Disk-scales mostly concealed, but radial shields 

 naked. 



o. — Ophiacanthella Ver. Basal rows of spines not approxi- 

 mate dorsally. Dorsal arm-plates largely in contact. Radial 

 shields long, mostly naked, in contact by their edges. Arm- 

 spines nearly smooth. Three tooth-papillae; mouth-papillae 

 four, conical, all similar. 



O. troscheli (Lym.) 



a. o. — Ophioscahis (p. 42) Dorsal arm-plates separated. 

 Basal rows of spines closely approximate dorsally. Radial 

 shields large, broad, naked, in contact for nearly their whole 

 length. Two or three tooth-papillae. Arm-spines thorny 

 and glassy. 



O. echimdata (Lym.) 



A. A. — The oral shield is separated from the side arm- 

 plates by the distal lobe of the elongated adoral shields. 



D. — Ofthiopristis Ver. Adoral shields narrow, trilobed, the 

 narrow distal lobe separating the oral shield from the side arm- 

 plate. Disk-scales usually concealed by cuticle and spinules. 



E. — Ofi/iiopora, gen. nov. (See p. 43). No tentacle-scales, 

 the pores are very large, spines small, usually smooth. 



O. bartletti (Lym.) One spiniform distal oral papilla by 

 the side of the oral tentacle-pore. Disk covered with acute 

 spinules. 



