EEPORT ON THE OPHIUROTDEA. 109 



tentacle scales, which are two-thirds as long as an under arm plate. Colour in 

 alcohol, pale straw. 



Station 172. — July 22, 1874 ; off Nukualofa, Tongatabu ; 240 fathoms ; coral. 



This species stands very close to Ophioconis miliaria of the West Indies, and comes 

 from a similar depth. It seems sufficiently distinguished by the arm spines, which are 

 more numerous by one or two, and more flattened, showing even a feeble tendency to 

 become spatulate. 



Species of Ophioconis not herein described. 



Ophioconis forbesii, Ltk., Addit. ad Hist., part 3, p. 98, 1869 ; Ludwig, Echin. des, 



Mittelmeeres, p. 546. 



PecUnura forbesii, Heller, Lit. Fauna d. Adriat. Meeres, 1862, p. 422, pi. ii. figs. 5-8; Zooph. 

 u. Echin. Adriat. Meeres, p. 57. 



Adriatic ; 15 to 50 fathoms. 



Ophioconis miliaria, Lym. (PI. XXXIX. figs. 7-9). 



Ophioconis miliaria, Lym., Bull. Mus. Comp. Zool., voL v., part 9, p. 221, pi. iii. figs. 49-51, 

 1878. 



Off Havana ; 450 fathoms. 



Ophioconis brevispina, Ludwig, Mittheil. der Zool. Station, Neapel., vol. ii. p. 61, 

 pl. iv. figs. 3^ 3^ 1880. 

 Mediterranean. 



Ojyhiochosta. 



Ophiochoeta, Ltk., Addit. ad Hist., part 3, 1869. 



Disk densely covered with smooth spines, or spines and grains. Numerous (7-10) 

 slender hollow spines. Numerous (10-14) small close-set mouth papillae. Teeth, but no 

 tooth papilla3. Two genital openings in each interbrachial space. 



In general appearance, the skeleton (Ophiochceta mixta) bears a likeness to that of 

 Ophioconis. The mouth frames are, however, smaller and more compact, their top being 

 covered by a stout three-sided peristomial plate, in one or two pieces, while their outer 

 open angle is more or less veiled by a thin lime crust. To the high, thin, and even genital 

 plate is attached a very thin scale of similar form and equal length. The arm bones are 

 delicate with thin wings ; those near the margin of the disk have an outer projection on 

 top. The scale-coat of the disk is fine and closely soldered, and the radial shields of 

 moderate size, three-sided and separated. 



See Plate XXXIX. figs. 15-17. 



(zool. CHALL. EXP. — PART XIV. — 1882.) 15 



