526 
ZOOLOGY OF THE FAR EAST. 
Corbicula japonica Prime. 
(Plate XXII, figs. 6, 7.) 
1864. Corbicula Japonica, Prime. Ann. Lyc. Nat. Mist. Neiv York. \'ITI. p. M. fi*;;. 15. 
1870. Corbicula Japonica, Prime, Amer. Journ Conch. V, p. 132. 
1877. Corbicula biformis, Reinhardt, Sitzungsber . Ges. Nat. Freunde. ]i. 70. 
1S77. Corbicula biformis. von ^Martens, id. p. 119. 
1878. Corbicula biformis, Reinhardt, op. cit., p. 189, pi. v, fig. 3. 
1878. Corbicula Japonica and C. biformis. Clessin. op. cit.. pp. 170. rc)4. pi. XXX. figs. 7. 8, 
])1. xxxviii, figs, 15, 16. 
i87c^. Cyrcna biformis and Corbicula Japonica, Kobelt, op. cit.. pp. 438. 443, ])1. xxi fig. 3. 
1907. Corbicula Japonica, Pilsbry op. cit., p. 157. 
■1907. Corbicula ni pponcnsis and \-ar. dclicatula, Pilsbry, op. cit.. pp. 159, 160, pi. vii figs. 3, 4, 
II, 12. 
In spite of the fact that Prime himself later ' considered his C . japonica to be 
synonj'mous with Lamarck's C. orientalis, I have, after examination of Lamarck's 
type-specimen of the latter species, decided to consider it as a distinct species. The 
shape, sculpture and the colour are quite distinctive, and there seems to be no 
justification for uniting the two species. An examination of a very large series of 
shells from Osaka, Yeddo, Yokohama, Tokyo, Uweno Lake, and Sandai-gawa, 
Satsuma, Kiushiu Island has led me to the conclusion that Reinhardt' s species 
biformis is also based on full-grown shells of C. japonica. The differences in the 
form and shape of the shells (for example Prime's description reads " shell is 
transversely oval, subtrigonal, nearly equilateral", while the shells described by 
Reinhardt are triangular rounded, with unequal sides, the anterior side being 
smaller than the posterior) disappear when a large series is examined. The 
sculpture also is very variable. The shining varnished epidermis is a very good 
diagnostic character of the species; it varies in colour from brown of various shades 
to black The nymphs are broad and nearly smooth while the double laterals of the 
right valve have the two teeth of the same size. 
Prime's description of the species is based on young shells only, and does not 
correspond in all respects with his poor figures of the .species. Reinhardt' s descrip- 
tion, on the other hand, is based on a large series of shells of all ages, and does not 
need any amplification. 
Prime gave " Japonia" as the type-localit}^ of the species, while Reinhardt's 
specimens probably came from Yedo. Von Martens collected large series of shells 
from Yokohama, and, as remarked above, the species seems to be wideh' distributed 
in Central Japan. 
RelationsJtips : — The species though allied to C. orientalis (I^am.) is quite distinct. 
Of the other Japanese species of ('orhiaila it is allied to C. sandai Reinhardt, but 
differs in the.shape, sculpture, the shining varnishy epidermis, and the hinge of the 
shells. 
1 Prime, Ann. Lyceum Nat. Hist. Nerv York, X p. 1 88 (1874). 
