136 Mr. P. S. Abraham on Fome Genera 



Hexahranchus pellucidalus, sp. nov. PI. VI. figs. 2, 2«-2 c. 



H. ellipticus, gibbus, pellucidulus, siibgelatinosus, albus ; pallio 

 baud multo expanse, ad dorsum lateraque Isevi vel subpustuloso, 

 pone interqiie tentacula dorsalia corrugato, margine integro undn- 

 lato ; tentaculis dorsalibus obtusis, laminatis, pediculatis, flectis, 

 opaeis, prorsum confertisque positis, et in Taginulas retraetilibus ; 

 branchiis parvis, ramosis, opaeis, non-retractilibus, in sex cristis 

 anum baud propinque circumdatis ; tentaculis bibialibus crassis, 

 planis, foliiformibus, margine crenato ; pede angusto, postice 

 acuminate, margine anteriore transverse diviso, cum lamina pos- 

 teriore fissa. 



The general shape is elliptical, convex on the back, rather 

 gelatinous. The mantle is comparatively not much expanded; 

 it is smooth or irregularly snbpustulose on the back j ante- 

 riorly, behind and between the dorsal tentacles, the surface 

 is less gelatinous, and is finely and distinctly puckered into 

 opaque pustules. The lateral expansions of the mantle^ 

 which, especially in small specimens, are not very wide, are 

 fleshy and have the margin wavy, subcrenulate, and more or 

 less reflexed in parts. The dorsal tentacles are short and 

 thick, kneed somewhat backwards, laminated minutely and 

 diagonally, with blunt rounded ajjices, retractile through short 

 sheaths set far forwards and near together. The branchisB 

 are small and bipinnate, and form six, more or less irregular, 

 non-retractile tufts at some little distance around the slightly 

 raised anal opening. The oral tentacles are free, leaf-shaped, 

 fleshy lobes, with crenate edge, and are set upon short pedun- 

 cles. The foot is narrow : in front it is transversely slit, the 

 anterior lamina being thin and entire, while the posterior is 

 rather thicker, somewhat lobulate, and mesially divided. The 

 mouth opens into the smaller end of a long, conical, muscular 

 pharynx with longitudinally plicated wall. The odontophore 

 is large, broad, and bilobed ; the lobes are applied together ; 

 and their touching surfaces are supplied with numerous trans- 

 verse rows of elongated, conical, recurved spines, none of 

 which are central or of different shape. The colour of the 

 spirit specimens is a transparent white, with the anterior 

 pustules, the edge of the mantle-border, the dorsal tentacles, 

 the branchiae, and the foot yellowish and opaque. 



The dimensions (in spirit) are — length 27 millims., breadth 

 21, height 12. 



Hah. unknown. 



H. lacera and H. pellitcidula form a well-rnarked section of 

 the genus. They resemble each other and differ from all the 

 other species of Hexahranchus in having the body raised and 



