﻿452 r.ASTENA 



Microcoiidxlus bonclli Dkoui;t, Jl. dc Conch., XX\ 1, 1879, p. 



138. " 

 Margaritana (Microcondyhca) boiicllii Kouelt, Icon., 1884, 



p. 62, pi, XXV, figs. 208, 209. 

 Leguminaia boncUii W'esterlund, Faun. Pal., II, Pt. 7, 1890, 



p. 191. 



Lamarck's brief description of Anodonta nniopsis entirely 

 agrees with the shell commonly known as Microcondyhca or 

 Monocondyhca hoiicHii. The statement that the ligament pass- 

 es into the hinge exactly frts this, and this is one of the best 

 generic characters of Leguminaia. 



The amount of variation of this species is very great. In 

 many cases the posterior end has evidently been injured by 

 unfavorable environment, and the shell is dwarfed and vari- 

 ously distorted, and sometimes a good deal thickened. Of 

 course every individual variation and distortion of this kind 

 has been seized on by the New School and elevated to specific 

 rank. I have seen only wdiat seemed to me a single species of 

 this subgenus, and nothing which really was worthv of a 

 varietal name 



Indeterminate species. 



Leguminaia nisibana Kop.elt, Icon., new ed.. XIX, 1912, p. 17, 

 pi. Dxx, fig. 2706. 

 Xisibis, Wilajet Diarbekir. 

 Described from a single left valve. 



Genus LASTEX'A Rafinesque, 1820. 



Lastena Rafinesque, Ann. Gen, Sci. Phys. I'rux.. 1820, p. 316. 



— Ortmann, Ann. Car. Mus., VIII. it)i_', p. 297. 

 Odatelia RaEinesoue, Atlantic jl. and b^riend. 1832. p. 154. 

 Leptodea (Rafincs(iue) Coxrad. Pr. Ac. X. Sci. Phila.. 1853, 



p. 262. 



Shell elongated, subsolid, inequilateral, generally wider in 

 front, rounded-truncate at anterior base, pointed at post-basal 

 region, and having a low posterior ridge, with one or more 

 secondarv ridges above it ; beaks low, sculpture consisting of 



