160 THE VOYAGE OF H.M.S. CHALLENGER. 



Species of Ojiluopdla uot herein described. 



Opkiopsilaaranea,Y\)S., Trans. Linn. Soc, vol. xix. p. 149, 1842; TAidwig, Ecliin. des 



Mittelmeeres, p. 550. 



Ojikianoplus marmoreua (1), Sars, Mul. Lit. Fcauna, p. 23, LS59. 

 Opliioimla marmorea, Ltk., Addit. ad Hist, part 2, p. 136, 1859. 



Mediterranean ; 15 to 40 fathoms. 



Ophiopsila annulosa, Ltk., Addit. ad Hist., part 2, p. 136, 1859 ; Ludwig, Echin. 

 des Mittehneeres, p. 551. 



Ophianojilti-s animlosus, Sars, Mid. Lit. Fauna, p. 83, pi. i. figs. 2-7, 1857. 

 Mediterranean. 



Ophio2)sila riisei , Ltk. (PL XL. figs. 1-3). 



Opliiopsila RUse:, Ltk., Addit. ad Hist., part 2, p. 136, 1859, pi. v. fig. 2. ; Lym., HI. Cat. Mus. 

 Comp. ZooL, No. i. p. 150, figs. 16, 17 ; Bull. JIus. Couip. Zool, vol. v., part 9, p. 228. 



West Indies ; littoral to 37 fathoms. 



Ophiopsila fulva, Lym., Bull. Mus. Comp. ZooL, vol. v., part 9, p. 227, pi. ii. figs. 

 25-27, 1878. 



West Lidies; 13 to 175 fathoms. 



Ophionereis. 

 Ophiiiiiercis, Ltk., Addit. ad Hist., part 2, 1859. 



Disk covered with fine overlapping scales, usually uniform, except those along 

 margin, which are somewhat larger. Radial shields nearly hidden by the scale coat. 

 Large oblong teeth. Mouth angle small and short, and Iwaring nine or ten close-set 

 little papillas. A few (three to five) short, smooth arm spines. One large tentacle scale. 

 Each upper arm plate has a supplementary piece on either side. Two genital openings 

 beginning outside the mouth shields in each interbrachial space. 



Seen from their under side, the radial shields are found to be long and narrow 

 with an enlarged outer end [Ophionereis reticulata), or wide and rudely three-sided 

 [Ophionereis anntdata), l^ut in either case they are widely separated. The genital plates 

 are long, club-headed and moderately stout, and have attached, just at the inner pai't of 

 the head, a thin genital scale, which extends quite to the mouth shield. The mouth 

 frames are rather simple and not large, about as large as in Amphiura, and the} support 

 very small jaws bearing a distinct jaw plate. There is nothing but an irregular lime 

 crust to represent the peristomial plate. The disk arm bones, beyond the first two, 

 have on their upper surface a long projection forward fitting into a slot in the next 



