A. M Verrill — North American Ophiuroidea. 345 



Oral papillae all similar. Dorsal arm-plates largely in contact. 

 Tentacle-scales one or two, all similar. Spines slender, finely serru- 

 late or nearly smooth. 



This genus is, in most respects, closely related to Ophiomitra. It 

 differs in having the disk-scales mostly concealed by cuticle ; in hav- 

 ing three apical tooth-papillae, instead of one ; in having the dorsal 

 arm-plates joined ; and in the smoothness of the spines. 



It is separated from Ophiacantha especially by the naked and 

 contiguous radial shields, and from the typical section of that genus 

 by having three tooth-papillse and contiguous dorsal arm-plates. 



Ophiopora Ver., 1899a, pp. 39, 43. Type, O. Bartletti (Lym.) Ver. 



Adoral plates with two distal lobes, one of which embraces the 

 lateral edge of the oral shield and separates it from the side arm- 

 plates, as in Op?iiopristis. No tentacle-scales ; tentacle-pores all 

 A^ery large and widely open. Two or three tooth-papillae. Outer 

 oral tentacle-pore is submarginal and furnished with one special, 

 acute, papilla or oral tentacle-scale on the adoral shield. Disk-scales, 

 above, and the radial shields are concealed by cuticle and spinules ; 

 on the under side the scales are visible. Arm-spines few, nearly 

 smooth. Dorsal arm-plates are separated by side plates. 



This genus is closely allied to Ophiolimna, but differs in the large 

 open tentacle-pores, without scales. 



Ophiopora Bartletti (Lym.) Yer. 



Ophiacantha Bartletti Lym., Bulletin Mus. Comp. Zool., vol. x, p. 256, pi. v, 



figs. 73-75, 1883. 

 Ophiopora Bartletti Ver., Ophiur. Bahama Exp., Bull., v, p. 39, 1899. 



This is the only known species of this group. The disk is covered 

 by slender acute spinules. The four arm-spines are small, tapered, 

 rather short, nearly smooth. The side arm-plates are not prominent. 



West Indies, 291 fathoms, Blake Exped. 



Ophiolimna Ver., 1899a, pp. 40, 44. Type 0. Bairdii (Lym.) Ver. 



Adoral shields trilobed ; one distal lobe extends back between the 

 oral shield and first side arm-plate, so that the oral shield is 

 detached from the arm. The jaws may bear more or less granules. 

 Disk-scales and radial shields covered with granules, or spinules, or 

 both. 



