42 NATURAL HISTORY BULLETIN. 



three tooth-papillae as the usual character of this division. 

 The species need revision as to the tooth-papillae. 



a. — Radial shields rather small, narrow, mostly concealed. 

 O. scutata Lym. 



O. ctispidata Ver. 



O. -pectinula Ver. 



a. a. — Ophioscalus, nov. Radial shields large, wide, closely 

 joined, naked. Disk-scales covered with rough spinules. 

 Arm-spines approximate dorsally. 



O. echinulatus (Lym.) 



Section C. — Ophiectodia, subgenus nov. 



Outer mouth-papillae (oral tentacle-scales) several, forming 

 a cluster or a double row, some often standing on the lower 

 face of the jaw or adoral shield. Tooth-papillae one to three, 

 or more. The mouth-papillae are clustered nearly as in typ- 

 ical Ophiomitra. 



O. enopla Ver. 

 O. rosea (Lym. ) 

 O. sped ab His (Sars.) 



Series II. 



Group D. Ophialccea, (subgen. nov.) Types, O. nuttingu 

 (Ver.) and O. tuberculosa (Lym.) (Seep. 38). 



The dorsal arm-plates are broadly in contact, at least on 

 many of the proximal joints. Disk-scales bear spinules or 

 granules. Radial shields separate, sometimes more or less 

 exposed distally, sometimes covered. Arm-spines rather 

 short, few, nearly smooth, the rows not approximate dorsally. 

 Mouth-papillae nearly as in typical Ophiacantha (group A). 



