278 Mr. E. A. Smith on the Genus Sphenia. 
Seventeen recent species have been described as belonging 
to this genus, as follows :— 
Sphenia Binghami, Turton. 1822. 
Swainsont, Turton, 1822. 
decussata (Mont.), Turton. 1822. 
californica, Conrad. 1837. 
Cleryana, @Orbigny. 1846. 
ornatissima, VOrbigny. 1846. 
alternata, @Orbigny. 1846. 
Riippellii, A. Adams. 1850. 
princeps, A. Adams. 1850. 
elliptica, A. Adams. 1850. 
LITTLE 
fils decurtata, A. Adams. 1850. 
14 - philippinarum, A. Adams. 1850. 
13. —— fragilis, Carpenter. 1857. 
14. —— bilirata, Gabb. 1861. 
15. ovoidea, Carpenter. 1865. 
iG: perversa, Blanford. 1867. 
Mee pacifica, Folin. 1867. 
Of the above, no. 2 has been shown to be the young of 
Mya truncata, no. 3 equals Petricola lithophaga, nos. 5, 6, and 
7 are species of Cuspidaria, nos. 4, 9, 10, 11, and 12 have 
since been removed to Cenrad’s genus Cryptomya, and no. 14 
appears to be a young Sazicava, as suggested by Carpenter* ; 
this, however, is uncertain until the type, if preserved, has 
been reexamined. | 
The following species—decussata, Deshayes, semistriata, 
Hanley, and mindorensis, Adams and Reeve—originally 
described by their respective authors as Mya, were subse- 
quently referred to Sphenia by A. Adams, but have since 
been definitely located in Cryptomya. In the Paetel Cata- 
logue, 1890, iii. pp. 20, 21, Rupicola distorta, Montagu 
(=concentrica, Fleur. de Bellev.), is erroneously classed with 
Sphenia. The shells of nearly all the species are very similar 
and liable to great variation in form, arising from the locality 
in which they live. The following are the species which 
belong to Sphenia as now understood. 
Genus SpHENIA, Turton. 
1. Sphenia Binghami, Turton. (Pl. XV. A. fig. 1.) B.M.t 
Sphenia Binghami, Turton, Conch. Ins. Brit. p. 56; Fischer, Man. 
Conch. p. 1122, pl. xxxiii. fig. 4. 
* Moll. West. North America, 1872, p. 118. 
T Species marked B.M. are in the British Museum. 
