1 172 LAMEI.IjnENS 



Unio corbeti Deschamps. Bull. Soc. Zool. Fr.. XVII, 1892, 



p. 68, fig. 

 Unio mainwaringi Simpson, Syn., 1900, p. 856. 

 LameUidcns mainwaringi Preston, Rec. Ind. Mus., VII, 1912, 



p. 306. 



More solid, less brilliant and more rhomboid than L. 

 thzvoitesii to which it is dangerously close. The type, whose 

 measurements I have given first, has been slightly injured on 

 the dorsal slope. 



Shells have several times been received bearing the name 

 Unio mainzvaringi Nevill, which seem to be the same as conso- 

 brinus or merely a small form of it. I cannot find that Nevill 

 ever described the species credited to him. 



Since the publication of the Synopsis, Preston, (1. c), has 

 published a description of Nevill's species as follows : 



"Shell rather small, cuneate, covered with a finely lamini- 

 ferous periostracum ; both valves marked with rather fine, 

 concentric and finer, transverse, radiate, scratch-like striae ; 

 dorsal margin anteriorly gradually sloping, posteriorly arched 

 and more rapidly descending; ventral margin somewhat 

 straight ; anterior side rounded ; posterior side angled above 

 and below, somewhat obliquely and obtusely rostrate; hinge- 

 teeth well developed, moderately short ; anterior adductor scar 

 deeply impressed, posterior scar somewhat roughly triangular, 

 well impressed ; interior of shell bluish, iridescent, rather gran- 

 ulate. 



Long. 25.5. lat. 50 mm." (Preston). 



Type locality, Siliguri ; also Namtsik Dihang. 



Lameleidens eameeeatus (Lea). 



Shell irregularly elleptical or subrhomboid, subinflated, 

 rather thin, inequilateral ; beaks moderately full and elevated, 

 their sculpture being the characteristic, curved, subradial bars ; 

 posterior ridge elevated, narrowly rounded, there sometimes 

 being one or two faint, radial ridges above it ; dorsal slope 

 obliquely subtruncate : dorsal outline nearly straight ; surface 

 almost smooth ; epidermis olive to olive-chestnut ; usuallv with 

 a smoky tint, more or less shining ; teeth much compressed ; 



