A. E. Verrill — North American OpJiiuroidea. 31'7 



Ophiocnida Lym., 1865 (restr.). Type O. hispida Lym., 1865. 



Ophiocnida Lym., 111. Catal. Mus. Comp. Zool., i, p. 133, 1865; pars, Voy. 



Challenger, p. 152, 1883. 

 Ophiocnidella Ljung., Of v. Kongl. Vet. Akacl. Forhandl., vi, 1871, p. 649 



(Type O. scahriuscula). 



Oral papillte three, subequal, arranged in a series along the jaw- 

 margin. Disk-scales distinct, bearing spinules or granules. Arm- 

 spines three to five. Radial shields divergent. Two tentacle-scales ; 

 rarely one. 



A. — Disk with numerous acute spinules. 

 a. — Arm-spines three, rarely four. 



O. hispida (LeC.) Lym. '65. Spines three. Disk with many 

 slender sharp spinules. Panama. 



0. scabriuscxda (Ltk.) Lym. '65. Spines three. Disk spinose. 

 Disk-scales thick. Oral papillae blunt, nearly equal. W. Indies. 



0. echinata Lym. '74. Spines four. Disk very spinose. Adoral 

 shields trigonal. Radial shields narrow. E. Indies. 



0. sexradia Duncan. Six rays ; four arm-spines ; one tentacle- 

 scale. E. Indies. 



aa. — Arm-spines five or six. 



O. scabra Lym. '79. Lowest spine thick and rough. Proximal 

 oral papilla apical and bead-like. Adoral shield lunate. Off Bahia, 

 1275 fath. 



AA. — Disk-scales partly bare ; partly with granules or very short 

 spinules, or both. 

 h. — Disk-scales large, in a rosette, mostly naked ; some marginal 

 and submarginal bear granules. Three arm-spines. 



O. filogranea Lym. '75. Radial shields wide, divergent. Adorals 

 lunate. Two tentacle-scales. Florida. 



hb. — Disk-scales smaller, many naked ; some marginal and sub- 

 marginal bear grains or small conical spinules. 



O. Zioveni (Ljng.). Disk-scales in a rosette; some at margin, bear 

 spinules; others below, bear granules. Outer oral papilla flat. Radial 

 shields touch distally. Rarely four arm-spines. Brazil. 



0. Lutkeni (Ljng. '71). A few submarginal and marginal scales 

 bear small spinules. Three arm-spines. Dorsal arm-plates wide, 

 usually broken into two or more parts. W. Indies. 



Trans. Conn. Acad., Vol. X. October, 1899. 



22 



