UNIO PHASEOLUS. 



SPECIFIC CHARACTER. 



Umbo compressed ; cardinal plate very thick ; lateral 

 tooth short ; surface radiated ; beaks simple. 



SYNONYMS. 



Unio PHASEOLUS. HUdreth. Journal of Science^ vol. xiv. 



p. 283. Short and Eaton^ TVansylvania Journ. of 



Medicine^ for February^ 1831. 

 Unio cuneatus. Var. Barne. (note to Hildreth's essay.) 

 Unio planulatus. Zea, TVans. ^7ncrican Philos. Soc. 

 N.S.Yo]. 3 pi. 9 p. 13. 



description. 



Shell transversly oblongovate, thick : surface yellowish 

 brown, with several rather broad radii, which are often in- 

 terrupted, by the larger lines of growth, into spots ; disks 

 and umbo compressed : beaks simple or not undulated : 

 not elevated : cavity of the hinge membranes or lunule oval, 

 acute : ligament not elevated : loithin white, somewhat 

 grooved obtusely : cardinal plate very thick, with a con- 

 siderable flattened space between the cardinal and lateral 

 teeth : cardinal teeth rather small, direct : lateral teeth ve- 

 ry short, oblique, and very thick : anterior smaller mus- 

 cular impression immediately anterior to the tips of the 

 lateral teeth. 



