DURING THE ' CHALLENGER ' EXPEDITION. SY 



except by its peduncle. There are seven pairs of laminar branchiae, and in all essential 

 particulars the anatomy is that of Asterope. 



I have pleasure in naming this fine species after Mr. Henderson of the Christian 

 College, Madras, to whom I am indebted for numerous specimens. 



The species was dredged by Mr. Henderson in Madras Harbour in a depth of 4-5 

 fathoms. 



Ctclastekope orbicularis, n. sp. (Plate XV. figs. 13-19.) 



Female. — Shell rather thin, subspherical (figs. 13, 14) : seen from the side almost 

 circular, height equal to five-sixths of the length ; beak short and sharp ; rostral notch 

 narrow and moderately deep, situated quite in the middle of the anterior margin ; seen 

 from above the outline is regularly ovate, tapering a little towards the posterior 

 extremity, which is evenly rounded off, and more considerably to the front, which is 

 somewhat obtuse. Anterior margins of the shell fringed with short fine hairs ; surface 

 smooth; colour light brown. Frontal tentacle (fig. 15) three-jointed; the second joint 

 short, last joint elongated, conical. Secondary branch of the antenna three-jointed 

 (fig. 16); first joint broad and fringed below with numerous fine hairs, second much 

 more slender and bearing a single short marginal seta, third very small and ending in 

 a single long ringed seta. The mandibular foot (fig. 17) is very similar to that of 

 C. hendersoni, except that the falciform process (which having been broken was only 

 partially seen) seems to be much smaller and less elaborately armed. Caudal laminae 

 (fig. 19) broad and short, bearing eleven marginal ungues, the first eight of which are 

 merely slender closely-set curved setae, nearly equal in length and slightly spinulose ; 

 the remaining three are very stout, strongly curved, and bear numerous marginal teeth, 

 the first of them about as long as the preceding setae, the second twice, and the third 

 fully three times as long ; abdominal margin in front of the lamina densely hairy. 

 Length of the shell 2-7 millim. 



I have seen only one specimen of this species. It bears the inscription " Valparaiso," 

 without any further particulars; and I am not sure whether I had it from the 

 Challenger' or from some other source. 



Genus Ctpkidina, Milne-Edwards. 

 Cypridina albomaculata, Baird. 



1880. Cypridina albomaculata, Baird, " Note upon the Geuus Cypridina, Milne-Edwards," Proc. 

 Zool. See. Lend., Annulosa, p. 201, pi. Ixxi. figs. 1, la, \b, \c, \d. 



The type of this species is in the British Museum, and is stated in Dr. Baird's 

 description to be from " Swan Kiver, — from the collection of Mr. Cuming." The 



n2 



