no Records of the Indian Museum. [Voi,. XXIV, 



1866. Unio foliaceus and Unio peguensis, op. cit., pp. 148, 154. 

 1868. Unio peguensis, Reeve, Conch. Icon. XVI, pi. xcv, fig". 519. 

 1876. Unio foliaceus, Hanley and Theobald, op. cit., p. 19, pi. xlii, 



fig- 3- 

 1889. Unio foliaceus, Tapparone-Canefri, op. cit., p. 345. 

 1900. Trapezoideus foliaceus, Simpson, op. cit., p. 858. 



1912. Trapezoideus foliaceus, Preston, op. cit., p. 307. 



1914. Trapezoideus foliaceus, Simpson, op. cit., pp. 1181, 1182. 



1915. Tvapezoideus foliaceus, Preston, op. cit., p. 193. 



1919. Trapezoideus foliaceus, Haas, op. cit., pp. 261, 262, pi. xxxii, 

 fig- 3- 



Anthony's Unio -peguensis is synonymous with this species 

 and is not referrable to the genus Pseudodon as Simpson believed. 

 Deshayes and Julien's Unio comptus is T. misellus, and the type 

 of Unio fragilis, Nevill, is a specimen of T. exolescens {vide p. 109). 

 Preston's new variety zaleymanensis is not a variety of this spe- 

 cies, but is based on young and half-grown shells of T. misellus. 



T. foliaceus is represented in the Indian Musuem collection by 

 specimens from Bhamo and Zaleyman, Burma. 



Trapezoideus dallianus (Frierson). 



1899. Unio foliaceus, von Martens, op. cit., p. 42. 



1913. Parreysia dalliaua, Frierson, Nautilus, XXVI, p. 142. 



1919. Trapezoideus dallianus, Haas, op. cit., p. 263, pi. xxxii, fig. 4. ) 



Frierson's species, as Haas has pointed out, is a Trapezoideus 

 and not a Parreyssia as the author of it thought. Haas has also, 

 I think, rightly referred von Martens' specimens of T. foliaceus to 

 this species. 



In the Indian Museum -there is a single right valve from 

 Burma, exact locality not stated, which belongs to this species. 



Trapezoideus misellus (Morelet). 



1912. 'Trapezoideus foliaceus var. zaleymanetisis, Preston, op. cit., 



P- 3»7; 



1915. 'Trapezoideus foliaceus var. zaleymanensis, Preston, op. cit., 



p. 194. 

 1919. Trapezoideus misellus, Haas, op. cit., pp. 266-270, pi. xxxii, figs, 



6-9, pi. xxxiii, figs. 1-5. 



Haas has given the complete synonymy of this species quite 

 recently. However, he wrongly included in it Nevill's Unio fragi- 

 lis, the type of which, as I have stated already , is T. misellus, and 

 he did not include in the synonymy Preston's var. Zaleymanensis 

 of T. foliaceus, which was described from young and half-grown 

 shells of this species. 



The species is represented in the Indian Museum collection by 

 a fair series of specimens of all ages from Tenasserim, the Irrawadi 

 River, Zaleyman and Bhamo. 



Trapezoideus subclathratus (v. Martens). 



1919. Trapezoideus subclathratus, Haas, op. cit., pp. 270-272, pi. 

 xxiii, fig. 6. 



