3 



14 DR. J. E. GRAY ON THE GENUS CUSCUS. [NoV. 12, 



lusca, pi. XXXIX. f. 3. Yet there is just that amount of difference 

 between tlie palette of these animals and those found in the young 

 specimen of Furcella which prevents one from saying that the animal 

 is absolutely the animal of the Furcella. 



The palettes of Furcella were slender, cylindrical, with a dilated 

 tip like a double-headed hammer, like the young palette of Teredo 

 malleohim of Turton, but of a much larger size ; and they had a 

 small, slightly-raised tubercle on the middle of the inner side of the 

 dilated end. 



The palette in the two specimens of Teredo which we have lately 

 received is of precisely the same form, and nearly of the same size ; 

 but instead of having this small tubercle, the middle of the dilated 

 end is produced into an elongated process about half an inch long, 

 which is more slender and oblong at the base, thicker, flattened, and 

 dilated above, and truncated at the top. 



The valves of the shell are exactly like those of the Teredo navalis, 

 T, norvegicus, and other normal species of the genus, but larger. 



I am inclined to name this species Teredo furcelloides ; for I 

 do not think it would be safe to decide, without further evidence, 

 that it is the animal of Furcella, Lamk. ; but at the same time I 

 consider it right to bring the occurrence of this animal at once before 

 the Society, as it has led me to doubt if my conclusion was correct 

 that Furcella is a genus of Conchiferous Mollusks without any valves, 

 as I was inclined to believe before the animal occurred, and which 

 the evidence then before me led me to believe was a correct conclusion. 



The palettes are situated at the hinder end, just within the edge 

 of the mantle, the siphons being quite distinct from or within their 

 base. The siphons are slender, of nearly equal diameter, and united 

 nearly to their tips ; in their contracted state they just reach to the 

 dilated part of the palette at the base of the terminal elongated pro- 

 cess. These are some fragments of a thin lamina of shell attached 

 to the hinder end of the mantle near the base of the palettes. 



II this should prove to be the animal of Furcella, or even of a 

 Ftircella-Wke Teredo, it shows most conclusively that the cup at the 

 end of the tubes cannot be regarded as the analogue of the true 

 valves of the genus, as I have also proved in a former paper (see 

 Proc. Zool. Soc. 185S, p. 258). 



If these animals prove to belong to the genus Furcella, as I sus- 

 pect they may, then that genus or group of species will only be 

 separated from the other Teredines by the habit of living in sand, 

 by the club-shaped form of the tube closed at the end with two 

 arched plates, the division and separate prolongation of the tubes of 

 the siphoual aperture, and the hammer-like form of the palettes. 



4. Additional Observations on the Genus Cuscus. 

 By Dr. John Edward Gray, F.R.S,, V.P.Z.S., etc. 



In the 'Proceedings' for 1858, p, 100, I gave some observations 

 on the genus Cuscus, with the description of a new species ; and 



