CONCHOLOGIA INDICA. 



21 



5, (). XJ. corrugatus, var. Itevirostris. — U. la;viros- 

 tris, Beusou, An. Nat. Hist. ser. 3, vol. 10 (18G2), 

 p. 191 (from types). 



River Godavcry; Pemgunga, &c. 



Benson's original examples were much worn at the 

 beaks, hence the name. A perusal of Schrijter's de- 

 scription of Mya corrugata, in his Fliissconchylien, 

 sho\vs that he was perfectly aware of the frequent 

 absence of the characteristic corrugation. 



7. IT. 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 Hani. Rec. Biv. Shells, 

 p. 19i, pi. 21, f. 50), Couch. 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. Yoiuig examples are oliva- 

 ceous yellow, changing to dark green on the very 

 concave posterior slope. 



PLATE XLV. 

 UNIO. 



1. U. crispatus, 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, ?*Iuller. — Mya c. Mliller, 

 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 diflPerent shells .is the 

 fragile and pellucid Mya corrugata of ^Mliller (Verm, 

 pt. 2, p. 214). His original description being utterly 

 insuificient, 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 f 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), pL 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 fi.shes. 



5. U. corrugatus. Typical form from Madras and 

 Southern India. 



G. U. Wynegungaensis, Lea, Proc. Ac. Nat. 

 Sc. Philad. vol. 8, p. 331 (Obs. Un. vol. 7, 

 p. 89), pi. 45, f. 151. — Reeve, Conch. Icon. LTnio, 

 f. S39. 



River Wynegunga, iS:c. 



