360 A. M Verrill — North American Ophiuroidea. 



flat, foliate or spatulate, recurved, in two or more divergent rows or 

 clusters, partly on the adoral plates. The arms can be turned up 

 vertically above the disk. 



Sub-family, OphiomycetinsB, nov. 



Disk with small but distinct scales, usually spinulose. No grapel- 

 shaped spinules on the arms. Arm-spines of the basal joints, and 

 sometimes the lower ones on some of the joints beyond the disk, are 

 flattened or spatulate ; others are long and slender. Tentacle-scales 

 of basal joints flat, often multiple. Upper arm-plates small, sepa- 

 rated. Side plates large, meeting above and below. Oral shield 

 small. Adoral shield long, carrying many of the spatulate oral scales. 



Internal mouth-frames slender; genital scales and plates broad, 

 flat, and curved up over the base of the arm. Arm-bones well 

 developed, but peculiar in form, and without a distal condyle. The 

 arm can be turned up vertically above the disk. 



Only four or five species are known. Two, 0. mirabilis Lym. 

 and O. frutectosxis Lym., are West Indian. 0. spathifer Lym. is 

 from off Japan, in 565 fathoms, and 0. grancUs Lym. is from the 

 South Atlantic, in 1000 fathoms. 



Sub-family, Ophiotholinse, nov. 



No visible radial shields. Disk-scales delicate, spinulose. Arm- 

 spines present on all joints, slender, about three ; associated with 

 the spines, beyond several basal joints, are clusters of grapel-shaped 

 spinules,* like those of Ophiohelas. A simple row of flat oral 

 papillae and tooth-papillae surrounds the proximal ends of the jaws. 

 Distally the oral papillae and oral scales are very numerous, in 

 several divergent rows, recurved, broad, flat, foliate or spatulate, 

 much as in Ophiomycetes. 



Several spiniform teeth. Tentacle-scales, on the basal joints, two 

 or more, flat; on other joints, spiniform. The side arm-plates meet 

 broadly below. Under arm-plates covered by cuticle. 



This group is closely allied to Op>hiomycetince, from which it 

 differs mainly in having grapel-shaped spinules on the distal joints 

 and in the more simple arm-spines. 



*Mr. Lyman describes these as " pedicellariee," but tbey are totally different 

 from all forms of true pedicellariae. They seem to me strictly homologous with 

 the curved hooks and booklets of Astronyx and allied genera, though much 

 more complex in structure. 



