102 TETHYS—AUSTRALASIAN. 
taceous; apex elevated, incurved, with a small callus, widely re- 
flected; upper margin sloped downwards, arched, excavated, 
rounded at the end ; outer lip anteriorly sinuously produced, dorsal 
margin obliquely arched, excavated. (Sowd.) 
The lower part of the dorsal margin, corresponding with the 
canal in spiral shells is much excavated. ‘This is the species to 
which was first applied by Pline the name of Lepus marinus or Sea 
Hare. (Sowbd.) 
Middle Harbor and Coodgee Bay, Port Jackson (Angas). 
Aplysia tigrina Rang, Aneas, P. Z.S., 1867, p. 228.—SowErsy, 
Conch. Icon., xvii, pl. 2, f. 5 (1869). Not A. tigrina Rang. 
The shell is longer, with shorter sinus than that of the true tagrina. 
Sowerby’s acute remark that this species is the Lepus marinus of 
Pliny must be taken for what it is worth. I support it only to the 
extent of agreeing that the animal is at all events a Lepus marinus. 
T. GIGANTEA Sowerby. PI. 58, figs. 28, 29. 
Shell large, expanded, convex, obliquely subquadrate, greenish- 
brown, concentrically undated and minutely striped, within a little 
testaceous, very pale rose; apex elevated, very little incurved, up- 
per margin wide, lightly arched, excavated ; inferior margin oblique, 
not excavated, anteriorly obliquely produced. (Sowbd.) 
Swan River (Cuming). 
Aplysia gigantea Sows., Conch. Icon., pl. 1, fig. 1a, b (Aug., 
1869). 
T. DENISONI Smith. 
Body (in spirit) high, exhibiting a distinct pedal disk, produced 
posteriorly into a caudal termination. ‘The entire surface wrinkled, 
dirty-whitish, black-veined in the wrinkles (? stains only). Mantle- 
lobes moderately large, commencing in front, some distance behind 
the posterior tentacles and terminating a little in advance of the 
cauda. Anterior tentacles large, cylindrical, with the apical slit 
not extending half way down the outer side, placed a little nearer 
the oral tentacles than the beginning of the mantle lobes. Eyes 
minute, situated near the outer anterior base of tentacles. 
Shell very thin, straw color, 30 millim. long and 27 broad. 
Animal about three inches in length in its contracted state 
(Smith.) 
Port Denison, Queensland (Coppinger) 
Aplysia denisont Smiru, Zool. Coll. H. M.S. Alert, p. 89 (1884). 
