EEPORT ON THE OPHIUROIDEA. 99 



This species and OpMomusium pulchellum, by theii* large flat side arm plates of the 

 first pair, and peculiar first under arm plate, which bears tentacle scales, are strongly 

 distinguished from others of the same genus. 



Off" Port Jackson ; 30 to 35 fathoms. 



Species of Ophiomusium not herein described. 



Ophiomusium eburneum, Lym., BuU. Mus. Comp. Zool., vol. i., part 10, p. 322, 1869 ; 

 111. Cat. Mus. Comp. Zool., No. vi., pi. ii. figs. 1-3 ; Bull. Mus. Comp. ZooL, vol. v., 

 part 9, p. 220. 



West Indies ; 230 to 325 fathoms. 



Ophiomusium testudo, Lym., 111. Cat. Mus. Comp. Zool., No. viii. part 2, p. 8, pi. i. 

 figs. 6-8, 1875 ; Bull. Mus. Comp. Zool, vol. v., part 9, p. 219. 

 West Indies; 100 to 177 fathoms. 



Ophiomusium planum, Lym., BuU. Mus. Comp. Zool., vol. v., part 9, p. 218, pi. iii. 

 figs. 46-48. 



West Indies ; 955 fathoms. 



Ophiomusium acuferum, Lym., 111. Cat. Mus. Comp. Zool., No. viii. part 2, p. 7, 

 pi. i. figs. 1-5, 1875 ; Bull Mus. Comp, Zool., vol. v., part 9, p. 219. 

 West Indies ; 42 to 220 fathoms. 



Ophiolipus. 

 OpMoUpus, Lym., Bull. Mus. Comp. Zool., vol. v., part 9, 1878. 



Entire animal covered with a thick, smooth skin, which more or less obscures the 

 underlying plates. Mouth papillaj. Teeth. No tooth papillae. Tentacle pores only at 

 the basal under arm plates, beyond these there are none. Upper arm plates rudimentary 

 and scarcely calcified. Two genital openings in each interbrachial space. 



Despite its thick, uncalcified skin, this genus stands very near Ophiomusium, from 

 which, however, it is further separated by the rudimentary upper arm plates, which 

 consist only of thin, disconnected, irregular fragments. 



Although apparently soft and naked, the disk skin, examined from the under side, is 

 found to be supported by very large oval radial shields, and by more or less crusty scales 

 and plates. The genital plates have a rounded shaft and a large clubbed head, to which 

 is attached a rather thin and long genital scale which shares in the articulation with the 



