I,AMEIvUr>KNS 1 177 



line arched : ]:)Ost-dorsal slope slopingly subtruncate ; surface 

 with stronq- concentric strife ; q^idermis brownish ; pseudo- 

 cardinals and laterals rather solid ; muscle scars impressed ; 

 nacre bluish-white. 



Length 94, height 51 mm. 



Assam. 

 Unio jenkinsianus Bknson, Ann. and Mag., X, 1862, p. 185. 



— Hanlev and Theobai^d, Conch. Ind., 1876, p. 19, pi. xli, 



fig. 4. 

 Lamellidens jenkinsianus Simpson, Syn., 1900, p. 857. 

 Lamellidens marginalis var. jenkinsianus Preston, Rec. Ind. 



Mus., VII, 1912, p. 305. 



I am at a loss to know what this is. Hanley and Theobald 

 think it may probably be considered an abnormal form of 

 U. marginalis or corriamis. It certainly cannot be the latter 

 but may possibly be the former. The figure bears some re- 

 semblance to that of an old Unio buckleyi. There is a shell in 

 the National Museum collection, which I refer to this with 

 considerable doubt, but it is not so solid as the figure given by 

 Hanley and Theobald show jenkinsianus to be. 



Lamellidens narainporensis Preston. 



"Shell cuneate, moderately convex, posteriorly rostrate, dark 

 reddish-brown, covered, towards the margins, with a finely 

 laminiferous periostracum, marked with concentric lines of 

 growth, bearing two carinse on each valve running from the 

 umbones in a dorsally posterior direction ; umbones small, not 

 prominent, somewhat coarsely corrugated; dorsal margin very 

 gently arched ; \^entral margin scarcely rounded in the anterior 

 and median regions, slightly curved posteriorly ; anterior side 

 abruptly rounded; posterior side sloping above, then angled 

 and very abruptly descending; cardinal tooth in left valve 

 obtrusely triangular, erect, absent in the right valve ; lateral 

 teeth anteriorly short, deeply grooved and projecting in the 

 right valve, erect and jagged in the left, posteriorly moderately 

 elongate and bifurcated in both valves ; anterior scars rather 

 circular, deep; posterior scars lightly impressed; interior of 



