18G6.] Contributions to Indian Malacology. 145 



No. 25. — Unio occatus, Lea. Bengal. 



Lea, Jour. Acad. Nat. Sci. Phil. 2nd Ser. V. 398, PI. 50, fig. 304. 



A compressed form, with strong teeth, fairly intermediate between 

 ccevuleus an&favidens, and allied to U. macilentus, Bs. and U. plagio- 

 soma, Bs. but more compressed than either. It especially requires 

 comparison with U. macilentus, of which it may be a compressed fomu 



No. 26. — Unio Gerbidoni, Eydoux. Coromandel. 



Said by Lea to be the same as Unio ccevuleus. 



No. 27. — Unio Bonneaudi, Eyd. South India. 



No. 28. — Unio Gaudiciiaudi, Eyd. Bengal. 



No. 29. — Unio Keraudrenii, Eyd. Chandernagore. 



I am indebted for all my information as to the above four species 

 to Mr. Benson. I have not access at present to the work in which 

 they are described. 



In Kuster's monograph of Unio in Martini and Chemnitz another 

 species is described from the " East Indies," U. Exanthematicus, Kiister, 

 p. 243, pi. 81, fig. 2. The authority, however, for the locality is Dr. 

 v. d. Busch, whose general accuracy, after the instances given above, 

 may be open to doubt ; the " East Indies" in a Natural History sense, 

 not many years since, denoted any country between Africa and 

 Kamschatka, and the peculiar pustulated surface of the shell, from 

 which the name is derived, is unknown in any Indian species. I 

 think it is probably not a native of the Indian Peninsula. 



U. discus, Lea, Trans. Am. Phil. Soc. IV, 74, PI. 18, /. 57, was at 

 first stated to be from India, on, however, palpably insufficient 

 grounds, the original specimen having been purchased from a dealer 

 amongst a lot of shells from India. The shell is so distinct from any 

 known Indian species, that I had concluded that the locality was 

 assigned to it in error, before I found that in a subsequent volume of 

 the Trans. Am. Phil. Soc, Vol. VIII., p. 234, note, Lea mentions 

 his having ascertained that the locality was the River Moctezuma in 

 Central America. 



Mr. Benson mentions (Ann. and Mag. Nat. Hist. 1862, X., 195,) 

 his having received from the Malabar Coast a shell which he refers to 

 U. consobrinus, Lea. 



