ZOOLOdlCAL RESULTS OF A TOUR EN THE FAR EAST. 
MOLLUSCA NUDIBRANCHIATA (ASCOGLOSSA). 
By Sir Charles Eliot, M.A., D.C.L., LL.D., K.C.M.G., C.B. {Principal of the 
University of Hong Kong). 
Dr. Annandale has kindly allowed me to examine numerous specimens of a 
small mollusca found by him in brackish water in the Siamese States on the east 
coast of the Malay Peninsula. They are referable to the genus Stiliger belonging to 
the group Ascoglossa. I agree with Pelseneer and others in regarding this group as a 
subdivision of the Nudibranchiata, although Bergh held the contrary opinion. 
For the genus Stiliger see especially Bergh, Malac. Unters. in Semper' s Reisen, 
Heft, iii, 1872, pp. 137 — 144 and id. Beitr. zur Kennt. der Aeolid. v, pp. 12—17. It 
belongs to the family Hermaeidae, all the genera of which are remarkable for their 
resemblance to Aeolids. It differs from the other members of the family in having 
large solid rhinophores which are not grooved or ear-shaped. The cerata are thick 
and inflated. The genus Ercolania, Trinchese, seems to be practically the same as 
Stiliger, from which it differs only in having a slight groove on the rhinophores. 
Another member of the Ascoglossa, namely Alderia modesta , is known to 
frequent brackish marshes in the British Isles. 
Dr. Annandale observes that though a careful search was made for hydroids or 
other coelenterates on which the molluscs might be feeding in the pools in which they 
were abundant, none were found. It is probable that the Ascoglossa live on the 
juices of algae which they pierce with their curiously shaped teeth. The fact that the 
radula is not used for mastication may account for the remarkable feature, charac- 
teristic of the family, that the front teeth are not broken off and thrown away when 
they become useless, as happens in most molluscs. 
Stiliger tentaculatus, sp. nov. 
The following are the notes on the living animal made by Dr. Annandale ; — • 
" The shape of the animal was slender ; its total length 13 mm. when fully 
expanded. (The specimens were remarkably uniform in size). The foot was 
narrow, much produced and sharply pointed behind, the greatest breadth of the sole 
being 3 5 mm. The head was slightly convex in front. The rhinophores were 
slender, nearly straight, pointed, each about 4 mm. long. The oral tentacles, which 
were situated slightly behind the rhinophores, were double ; the anterior processes 
were considerably shorter than the rhinophores, but a little longer than the posterior 
ones, over which they were usually held retro verted in a semicircle. The posterior 
processes, which curved backwards very slightly and were rather stouter than the 
