94 Records of the Indian Museum. [Voi,. XXIV, 



sis and probably represents another species of the genus. Owing, 

 however, to a single young shell being available I do not feel 

 disposed to consider it as a distinct species but a figure of the 

 unique specimen (pi. II, fig. 5) is published for future reference. 



Genus Indonaia Prashad. 



1918. Indonaia, Prashad, Rec. Ind. Mus. XV, pp. 148-148, fig. 2. 

 1921. Indonaia, id., ib., XXII, p. 602. 



Six species of this genus are known to occur in Burma. 

 Of these J. caerulea has a wide distribution throughout India and 

 Burma, I. bonneaudi and /. pachysoma occur in Assam and 

 Burma, /. crispisulcata and /. chaudhuni are only known from 

 Burma, while /. crispata has a wide range in Burma, Siam and 

 Cambodia. 



Indonaia caerulea (Lea). 



1889. Unio leioma, Tapparone-Canefri, op. cit., p. 344. 



1914. Nodularia caerulea, Simpson, op. cii., pp. 978-980. 



1915. Nodularia caeruleus, Preston, op. cit., pp. 136, 137. 



As a result of my examination of the large series of specimens 

 of this species in the Indian Museum, I am able to confirm 

 Simpson's conclusion that Unio gerbidoni Eydoux, Unio humilis 

 Lea, Unio corrianus Kiister, Unio leioma Benson, Unio filatus 

 Lea, Unio evitatus Lea, Unio trirosiris Sowerby and Unio ander- 

 sonianus Nevill (part onty) are synonyms of this species. 



This is the commonest species of the genus throughout India 

 and Burma and it is represented by a large series of specimens in 

 the Indian Museum. 



Indonaia bonneaudi (Eydoux). 



1889. Unio Bonneaudi, Tapparone-Canefri, op. cit., p. 343. 



1914. Nodularia bonneaudi ', Simpson, op. cit , pp. 988, 989. 



1915. Nodularia bonneaudi, Preston, op. cit., pp. i-jo, 141. 



I have not seen the specimens referred to this species by 

 Tapparone-Canefri, but have no doubt as to his identification. 



The species is widely distributed in Assam and Burma and 

 is represented by a large series of shells in the Indian Museum. 

 The specimens show great variation both as regards shape and 

 colour. Normally they are oval or ovate but some are distinctly 

 rostrate posteriorly ; in colour they vary from yellowish green to 

 dull brown or even black. 



Indonaia chaudhurii (Preston). 



1912. Nodularia chaudhurii, Preston, Rec. Ind. Mus. VII, p. 290. 



1914. Nodularia chaudhurii, Simpson, op. cit., p. 988. 



1915. Nodularia chaudhurii, Preston, op. cit., p. 140, fig. 7 (i, 2). 



I am not quite certain as to the validity of this species. 

 The only specimens 1 have seen are the type-series of Preston. 

 They come very near J. bonneaudi , but the shells are shorter, more 



