1922 ] B. Prashad : Burmese Unionidae. 103 



mostly consists of this species, the remainder being young shells 

 of Indonaia caerulea. 



P. smaragdites, as was noted by Benson, is characterized by 

 the shells being of a beautiful green colour interspersed with 

 lemon-yellow in the middle, the beaks being submedian and 

 greatly deflected forwards, with deep cavities and a well-marked 

 lunule. 



Benson's specimens were taken in the Berbampooter (Brahma- 

 putra) River, Assam, but the species is now known to have a wide 

 range in Burma and Assam. 



Parreyssia burmanus (Blanford). 



1869 Unio burmanus, Blnnforcl, Proc. Zool . Soc. London, p. 449. 



1875. Unio vtilcanus, Hanley, Proc. Zool. Soc. London, p. 606. 



1876. Unio burmanus and Unio vulcanus, Hanley and Theobald, 



op. rif.. p. 19, pi. xlii. fit;'. 7 and p. n_>, pi. civ, fijr, }. 



1878. Unio burmanits, Ncvill, op. cit., p. 900. 



1879. Unio burmanus, Tapparone-Canefri, op. cit., p. 343, 



1890. Unio burmanus and Unio vulcanus, Paetel. op. cit., pp. 146 and 

 172. 

 ? 1899. Unio burmanus, von Martens, op. cit., p. 38, pi. v, fig. 5. 

 1900. Parreysia burmanus and P. vulcanus, Simpson, op. cit,, p. 845 



and p. 844. 

 1912. Parreysia pernodulosa. Preston, Rec. hid. Mus. VII, p. 300. 



1914. Parreysia burmanus, Simpson, op. cit., p. 1120. 



1915. Parreysia burmanus, P. pernodulosa. and P. vulcanus, Preston, 



op. cit., pp. 170, 164, 168. 



The only specimen of this species which I have seen from Fea's 

 collection is a half-grown individual. It is decidedly longer in 

 proportion to the height and is abnormal so far as the sculpture 

 is concerned. The nodular sculpture which is a characteristic of 

 the umbones of the young and half-grown shells of this species is 

 quite obsolete and the radial sculpture over the rest of the beak is 

 also feebly developed. 



The specimens figured by von Martens {loc. cit.) are, in my 

 opinion, not referrable to this species and I have therefore included 

 a reference to his notes on this species with a reservation onl}'. 

 Hanley's Unio vulcanus, which was described from a single speci- 

 men and later figured by Hanley and Theobald in the Conchologia 

 Indica, is undoubtedly based on a young specimen of this species. 

 Some of the half-grown shells from Bhamo in the Indian Museum 

 collection answer to Hanley's description and are quite like the 

 figure of the type-shell in the Conchologia Indica. According to 

 von Martens {Joe. cit., p. 38), however, the young shells of Unio 

 tavoyensis resemble the figure of the type of U . vulcanus. Preston's 

 P. pernodulosa is based on very young shells of this species. 



The types of this species along with a large series of speci- 

 mens from the type-localit3 r , the Irrawadi River near Bhamo, are 

 preserved in the Indian Museum. The types of Preston's P. 

 pernodulosa were collected by Dr. Anderson at Zaleyman in Upper 

 Burma ; Fea's specimens were taken at Teinzo in the Mule 

 Stream, north-east of Bhamo. 



