150 CORBULIDJE. 



SPH.^NIA, Turton. 



S. BINGHAMI, Turton. 



S. Binc/hami, Brit. Moll. i. p. 190, pi. 9. f. 1, 2, 3. 

 Animal elongated, compressed, pale yellowish- white ; mantle 

 closed, except a passage anteally for a small, narrow, sub- 

 cylindrical foot, of a bluish transparent colour, with a 

 byssus of coarse filaments, and another for the anal and 

 branchial tubes. The anal siphon is short, but the longest of 

 the two ; it is encircled by 5-6 rough white cirrhi, and emits 

 a large, subhyaline, delicately frosted valve, which, on each 

 step of the animal in advance, is considerably exserted, and 

 then suddenly withdrawn ; the branchial siphon is little more 

 than a sessile orifice, but in connection with the anal one, 

 and, like it, furnished with 5-6 rough white cirrhi. The 

 branchiae are of a pale brown, the under one being the largest, 

 and runs horizontally ; the upper is much smaller, and laps on 

 the other obliquely ; the branchial vessels are so minute as to 

 give the laminse the appearance of smoothness ; there is, on each 

 side, at least one subtriangular, pointed, well-striated palpum, 

 and it is probable there is a second that has escaped detection. 

 This animal has great affinity to Saxicava, besides alliances 

 with Corbula and My a ; indeed the genus Sphcenia is almost 

 unnecessary, as its animal is nearly identical with Saxicava 

 arctica, and the structure of the hinge and the other hard 

 parts have much the same generalities. In our dubiety 

 whether this animal ought to be deposited in Sphcenia or 

 Saxicava, we have cut the Gordian knot, by adopting, con- 

 trary to our particular views, an almost superfluous genus, 

 being in some measure stimulated to this resolve by the 

 respect we entertain for the memory of our old talented 

 friend Dr. Turton, its founder, whose numerous works are so 

 highly valued by conchologists. 



PANDORA, Lamarck. 

 P. OBTUSA, Leach et Auctorum. 



P. obtusa, Brit. Moll. i. p. 210, pi. 8. f. 5 ; (animal) pi. G. f. 10. 

 Animal suboval, somewhat elongated ; the left side is more 



