106 TETHYS-INDIAN OCEAN. 



dilated and fringed anterior tentacles and for the peculiar notched 

 and inflexed character of the posterior tentacles. It was found 

 crawling among the fuci in small pools left by the receding tide on 

 the flat coral shores of Typinsan, one of the Meiacoshima group (J.. 

 Ad.). 



T. L^EVIGATA Stimpson. 



Smooth, convex, oblong, somewhat produced anteriorly ; lobes 

 of the mantle rather short ; siphon conical ; foot with a blunt pos- 

 terior termination ; dorsal tentacula cylindrical, orals dilated at 

 their extremities. Color, brownish above, sides with small dark 

 gray spots and a few patches of white punctse ; head and foot green. 

 Shell suboblong, very thin and membranaceous, of a pale horn 

 color ; arcuated incision short but deep ; summit triangular, small, 

 thick and callous. Length 2 inches. (Stimp.). 



Ousima (U. S. N. P. Exped). 



Aplysia Icevigata STIMP., Proc. Acad. Nat. Sci. Phila., 1855, p. 

 378. 



T. JAPONICA Sowerby. PL 18, fig. 22, 23. 



Shell obliquely ovate, subpellucid, obscure chestnut, within very 

 little calcareous, back tumid in the centre, with a slight rib and 

 depression near the dorsal margin ; apex elevated, much incurved, 

 biauriculated ; upper margin sloped, deeply excavated, short, 

 rounded at the end ; outer lip round, lower margin subquadrate,. 

 dorsal margin a little arched. (Sowb.~). 



Japan (Cuming).. 



Aplysiajaponica SOWB., Conch. Icon., xvii, pi. 5, f. 16a, b (1869). 



The biauriculated character of the apex is produced by the curv- 

 ing of the lateral margins on each side. (Sowb.). 



VII. Species of the Western Indian Ocean, Red Sea to the Cape. 



The more important external structural characters of several of 

 the species of this area are unknown. The synopsis following is 

 therefore quite imperfect, and founded largely on the extremely un- 

 satisfactory features of coloration. 



a. Small ; mantle with a large submedian orifice ; shell very con- 

 vex, nigrocincta. 

 aa. Large or moderate sized ; no large mantle-orifice so far a* 

 known, 



