CONCHOLOGIA INJDIOA. 
21 
5, 6. U. corrugatus, var. Isevirostris.— U. lseviros- 
tris, Benson, An. Nat. Hist. ser. 3, vol. 10 (1862), 
p. 191 (from types). 
River Godavery; Pemgunga, &c. 
Benson’s original examples were much worn at the 
beaks, hence the name. A perusal of Schroter’s de¬ 
scription of Mya corrugata, in his Fliissconchylien, 
shows that he was perfectly aware of the frequent 
absence of the characteristic corrugation. 
7. U. lamellatus, Reeve (as of Lea, Trans. Amer. 
Phil. Soc. s. 2, vol. 6, and Obs. Un. vol. 2, p. 19, 
pi. 6, f. 16, from which Hanl. Rec. Biv. Shells, 
p. 194, pi. 21, f. 50), Conch. Icon. Unio, f. 511. 
Pegu. 
Closely allied to U. generosus. The teeth, however, 
are peculiarly elongated. The form delineated is 
abnormally high ; other examples since obtained are 
much narrower, and more like Lea’s figures. The 
long lamellar hinge-teeth referred to by Lea, are very 
manifest, but whether the species is distinct from gene¬ 
rosus may be doubted. Young examples are oliva¬ 
ceous yellow, changing to dark green on the very 
concave posterior slope. 
PLATE XLV. 
UNIO. 
1. U. erispatus, Gould, Proc. Boston Soc. N. Hist, 
vol. 1, p. 141 ; Otia Conch, p. 191. 
Tavoy, Birmah. 
The specimen figured was sent to Benson by the 
American describer. 
2 to 5. U. corrugatus, Muller.—Mya c. Muller, 
Beschaft. Ges. Naturf. Berlin, vol. 4, p. 58, pi. 3, 
f. 7.—Chemn. Conch. Cab. vol. 6, p. 31, f. 22 
(from which Kust. ed. Chemn. Unio, pi. 97, f. 3, 
4).—Mawe, Lin. Conch, pi. 4, f. 3.—Not of 
Martini and Wood (as Mya) or Reeve (as Unio).— 
Mya spuria, Gmel. Syst. 3222, from Schroter, 
Einleit. pi. 7, f. 5 (copied as U. concentricus, 
Valenc. in Enc. Meth. pi. 249, f. 3). 
Near Madras; River Godavery ; Nagpore ; 
Pemgunga, &c. &c. 
Authors have recognised very different shells as the 
fragile and pellucid Mya corrugata of Muller (Verm, 
pt. 2, p. 214). His original description being utterly 
insufficient, had better be ignored; he defined the 
species, however, by his figure in the Berlin journal. 
We know of no adequate representations in the older 
works, hence Wood supposed it to be the very coarsely 
sculptured Cingalese (?) species, which we have called 
Tennentii, whilst Benson and others thought itfavidens. 
The views of the exterior given by Chemnitz and 
Mawe are indefinite, the outlines of the interior (and 
the hinge in Mawe’s figure) suit the present species. 
The range of character from entire smoothness (except 
near the tips) to a coarse divaricate corrugation over 
the dorsal half of the surface, from tumidity to com¬ 
pression, from thinness to solidity, from olive green to 
ochraceous green, can only be rivalled by its diversity 
of contour; every link, however, has been most cau¬ 
tiously traced. We believe that the U. Nagporensis of 
Lea (Journ. Ac. Nat. Sc. Philad. ser. 2, vol. 4, and 
Obs. U. vol. 7, p. 88, pi. 45, f. 150), will also prove a 
large variety, with worn beaks, of our form fig. 3, but 
dare not assert so positively. 
2. Var. solida, from the River Godavery. 
3. Var. Nagporensis. — ? U. Nagporensis, Lea, 
Journ. Ac. Nat. Sc. Philad. ser. 2, vol. 4 (Obs. 
Un. vol. 7, p. 88), pi. 45, f. 150. 
Nagpoor ; Pemgunga. 
The coincidence of locality and the general con¬ 
tour render it probable that Lea founded his spe- 
cies upon a worn aged example of this swollen 
form. 
4. Var. fragilis. 
A thin ventricose form, which, we are assured, has 
been taken from the inside of fishes. 
5. U. corrugatus. Typical form from Madras and 
Southern India. 
6 . U. Wynegungaeusis, Lea, Proc. Ac. Nat, 
Sc. Philad. vol. 8, p. 331 (Obs. Un. vol. 7, 
p. 89), pi. 45, f. 151. — Reeve, Conch. Icon. Unio, 
f. 339. 
River Wynegunga, &c. 
