900 MOLLUSCA. 



var. CORBIANA, Lea. 



Unio corrianus, Lea, Trans. Am. Phil. Soc, v, pi. ix, fig. 25. 



U. marginalis, var. corriana, Con. Indica, pi. xliv, fig. 4; Nevill, I. c, p. 38. 



Eour magnificent specimens of this very marked variety were found at Yaylay- 

 maw ; the nacre is of the most beautiful salmon-pink colour ; the only difference 

 from typical Bengal specimens is that the texture and teeth are thicker, and this is 

 the case also with specimens from Pegu. 



Long. 115, lat. 55 mm. 



Unio feddeni, Theob. Plate LXXX, fig. 11. 



Unio feddeni, Theob., Journ. As. Soe., Bengal, 1873, pi. xvii, fig. 3; Nevill, I. c, p. 38. 



Tolerably abundant in rice fields at Bham6, also at Yaylaymaw. I feel 

 quite sure that Mr. Theobald is wrong in recording this species as found in the 

 Pemgunga, Central India ; typical specimens from Mr. Pedden are marked in the 

 carefully kept collection of Mr. H. P. Blanford as from Burma; the specimens 

 found by Dr. Anderson in Upper Burma confirm Mr. Blanford's record of the 

 locality of the original type form, as opposed to that given by Mr. Theobald ; Mr. 

 Pedden collected in both localities. 



Unio BUHMANrs, Blanf. 



Unio burmanuSjBlBJii., VwG. Zool. Soc, lS69y 1^. 4<63; Con. Indica, pi. xlii, fig. 1; Nevill, I. c, 

 p. 38. 



This form was not found on the Second Yunnan Expedition. Pull-grown shells 

 are narrower and more produced, with the umbones much less prominent, and the 

 rugose sculpture also less developed than is the case with Z7. bhamoensis. 



The types of U. harmanus from Bham6 are in the Indian Museum. 



Unio bhamoensis, Theob. 



Unio bhamoensis, Theob., Journ. As. Soc, Bengal, 1873, p. 207, pi. xvii, fig. 1 ; Nevill, I. c, p. 39. 

 Unio mandelayensis, Theob., Journ. As. Soc., Bengal, 1873, p. 208, pi. xvii, fig. 2. 



Not uncommon at Myadoung and Yaylaymaw ; found also on the Pirst Expedi- 

 tion at Mandalay, Bhamo, and Shienpagah. The two above forms can certainly not 

 be separated, as indeed might have been surmised from Mr. Theobald's remarks in 

 the original description, large series from one locality showing that both varieties 

 run one into the other. The Pegu form mentioned in the original description of 

 Z7. hJiamoemis differs a good deal more from both than the Bhamo from the Manda- 

 lay one ; it is a pity Mr. Theobald did not give this Prome variety a name, instead 

 of the Bhamo one. 



