902 



MOLLUSCA. 



of the varieties of 77. ccsndeus, Lea. It is easily distinguished from U. bomieaudi 

 by its more irregular shape, thinner texture, by the acute angulation, greater pro- 

 duction posteriorly, and by the more developed sculpture ; a constant character also 

 is the pink colom' of the nacre, which in TJ. bomieaudi is bluish-white; this is 

 equally distinct and characteristic in young as in old specimens. 



Type from Myadoung ; long. 32, lat. 15|^, crass, llf mm. 



Specimen of TJ. honneaudi from Myadoung ; long. 31, lat. 18, crass. 13 mm. 



Family— CTBENIT)^. 

 Genus Ooebictjla, Meg. 



COKBICULA LAMARCKIANA, Prime. 



Corbicula lamarcliana, Prime, Ann. Lye. N. York, 1867 ; Nevill, I. c, j). 40. 



Specimens obtained at Hotha and Momein (5,500 feet) in Yunnan, and also at 

 Mandalay, agree exactly with Prime's original figure. Lieutenant- Colonel Godwin- 

 Austen also found a small form of this well-marked species at Manipur, in the 

 Kuchai stream. 



Long. 28|, lat. 20 J, crass. 13 mm. 



COKBICITLA TTJNNANENSIS, Nevill. 



Corbicula yimnanenm, Nevill, Joum. As. Soe., Bengal, vol. xlvi, 1877, p. 40. 



Medium-sized specimens from Yaylaymaw agree fairly with Prime's figure and 

 description of C. Unneana,^ the principal difference being the less truncate anterior 



Fig. 32. 

 Corhicula yimnanensis, nat. size. 



side. Shell large, thick, transverse, inequilateral, compressed, rather abruptly tumid 

 towards the umbones ; anteriorly moderately produced and rounded, posteriorly 

 produced and truncate (exactly as in Prime's figure of C. linnecma) ; lateral teeth 

 curved, the anterior a little more so than the posterior ; no lunule ; epidermis dark 

 brown, stride regular and close ; interior violet, of a darker shade near the margin. 



1 Ann. Lyo. N. York, 1867. 



