OPISTHOBRAN'CHIATA FROM THE ABROLHOS ISLANDS. 533 
the larger, so that the last two or three teeth consist simply of a narrow 
oval basal plate. All the types of teeth differ from the corresponding ones 
in T. gigantea. 
The genital aperture lies a little to the right of the middle line, just under 
or very slightly in front of the anterior edge of the mantle, and from it the 
quite distinct seminal groove passes forwards to the penis, which, iis noted 
above, lies just in front of and below the oral tentacle. 
The anus is situated at the hinder end of the visceral hump^ practically in 
the mid-dorsal line and a short distance away from the hump, upon a fold of 
the mantle. In the neighbourhood of the anus the mantle is thickened and 
projects outwards in the form of a flap, which is coiled round in such a manner 
as to form a funnel, the anal funnel, which in this species is relatively larger 
than in T. punctata. 
Notes. In all, five specimens of this species were obtained : two large ones 
about the same size from Wooded Island, two smaller ones with no exact 
locality given, and one quite small one from Pelsart Island. Professoi- Dakin 
in his paper on the Abrolhos (32, p. 170), when dealing with Wooded Island, 
makes the following reference, presumably to this species : " Nudibranchs and 
Tectibranchs [Aplysia sp.) were extremely common. We could have 
obtained hundreds of specimens of Apli/sia by merely ])icking them up as we 
waded in the shallow water." 
Smith (70, p. 89) described a form Aplijsia denisoni collected by H.M.S. 
'Alert' in the following manner : — 
" Body (in spirit) high, exhibiting a distinct pedal disc, produced jios- 
teriorly into a caudal termination. The entire surface dirty whitish, black- 
veined in the wrinkles (? stains only). Mantles-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 halfway 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 the tentacles. 
Shell very thin, straw-colour, 30 mm. long and 27 broad. Animal about 
three inches in length in its contracted state." 
This description, while not very exact, applies closely to the present speci- 
mens. It was, however, of an animal obtained from Port Denison, Queens- 
land, and I should have hesitated to regard it as identical, hud it not been 
possible to examine the original type-specimen in the British Museum. 
Smith's specimen, much discoloured by age and not well preserved, and the 
shell, dried and somewhat shrivelled, are still available. Taking into account 
the difference in condition of the specimens, I can see no way of distin- 
o-uishing between them, and so I have placed the present forms under Smith's 
name, although they come from fairly widely-separated areas. 
