OPHIUROIDEA OF THE BAHAMA EXPEDITION. 37 



f.f. — The distal oral papillae, or oral tentacle-scales, are 

 clustered or form a double row; all spiniform. Tentacle- 

 scales spiniform. 



* O. eno-pla Ver. 



e. e. — Basal rows of spines not very closely approximate 

 dorsally. Mouth-papilke in a simple row. 



* O. fraterna Ver. 

 O. cosmica Lym. 



d. d. — Arm-spines decidedly thorny or prickly, and usually 

 glassy, mostly long and slender. 



g. — Basal rows of spines approximate dorsally. Side arm- 

 plates very prominent. Disk with small slender crotch- 

 ets or branched spinules. 



O. asflera Lym. 



* O. millesfiina Ver. 

 O. -pentacrinus Ltk. 

 O. scutata Lym. 



g. g. — Basal rows of spines not closely approximate dors- 

 ally. Disk with short thorny stumps. 



O. steUata Lym. 



C. C. — Disk entirely covered with tapered spinules or true 

 spines, or having more or less of them mixed with gran- 

 ules or other structures, or else covered with granules 

 only. 



h. — Disk covered with spinules. only, or else having spin- 

 ules mixed with other structures, not granulated. 



i. — Disk with spinules only or mainly. 



j. — Basal rows of spines approximate dorsally. 



