18GG.] Contributions to Indian Malacology. 14? 



Kiister's type is narrower anteriorly and has rather different, coarser 

 plication posteriorly, than Lea's. It may be a different shell. 



No. 34.— Unio Nuttallianus, Lea. Assam, teste Benson. 



Lea, Jour. Acad. Nat. Sci. Phil. III., 310, pi. 30, f. 25. 



The locality is simply stated to be India by Lea. Benson, Ann. 

 and Mag. Nat. Hist. 1862, X , 194, states that he has received' speci- 

 mens from Assam. The volume containing the description of this 

 shell is not procurable in Calcutta. 



No, 35.— Unio Jenkinsianus, Bens. Burhampooter River, Assam. 



Benson, Ann. and Mag. Nat. Hist. 1862, 3rd Ser. X., 185. 



An ally of U. marginalia, distinguished by " the very tumid form, 

 the sloping posterior end, absence of a wing, the short ligament, and 

 the nature and position of the teeth." (Bens. 1. c.) In the Asiatic So- 

 ciety's collection there is a shell from Bhagulpoor perhaps referable as 

 a variety to this species. 



No. 36.— Unio pachysomia, Bens. Burhampooter Biver, Assam. 



Benson, Ann. and Mag. Nat. Hist. 1862, 3rd Ser. X., 186. 



" An inflated form of the ccerulcus type." (Bens. 1. c.) Mr. Benson 

 also states that he has received a distorted variety from Calcutta. A pe- 

 culiar tumid form which is not uncommon in Calcutta tanks is doubt- 

 less referred to. It agrees generally with the description given. This 

 form therefore adds one more to the Bengal list. 



No. 37.— Unio Smaragdites, Bens. Burhampooter Biver, Assam. 

 Benson, Ann. and Mag. Nat. Hist. 1862, 3rd Ser. X., 190. 

 A shell allied to U. favidens. 



\ Besides these forms a variety of U. favidens, Bens. (yar. martens) has 

 already been quoted as occurring in Assam. Mr. Benson also records 

 the receipt of a variety of U. cceruleus (J. A. S. B. VI. 750) and of a 

 small variety of U. marginalis (Ann. and Mag. Nat. Hist. 3rd Ser. X. 

 186) from that region. 



III. — Ceylon. 



No. 38.— Unio Layardi, Lea. Ceylon. 



Lea, Jour. Acad. Nat. Sci. Phil. 2nd Ser. IV., 243, pi. 36, f. 122. 



This is a shell of the marginalis type with a convex dorsal margin, 

 and generally rounded outline. It appears to be a fairly distinguish' 

 able form, though very close to Bengalensis and lamellatus. 



