- 580 - 



Superfamily L E P T N A ,., .^ . 

 Family leptonidae. 

 Gemis ?:HyOirA lanBrcfe. 

 SulDis-eiiiis .^rj; cilia s. s. 



ERYCILii v.oAJD?Ji.TA ( GablD ) . 



I7eaerom:'a niiadrata Ga'^'b , 1875, Trans. Ai:i. Philos. Soc . , new ser., 

 vol. 15, p. 247. 



ITeaerom.ya qu.adrata Ga^olj, 187?;, Proe. Acad. Nat. 3ei., Philadel- 

 phia, for 1872, p. 274, pi. 10, fxP'S. 4, 4a-'b. 



Description .- "Shell small, roimded, sixb- quadrat e ; bealics 

 posterior; aiiterior end ^^.T'oduce''"'. , rou,"de''' , ar.ri RTio-iTtly narrow- 

 ed; posterior end hroad^ly romided; hs.se nearly/ straight. 3vx- 

 face polished, narlred onlj hy minute lines of gr:OT;th. Length 

 .3 inch, height .25 inch." (Gab^T, 187".) 



"..... hiaee V7ith a prominent tooth in the right valve, 

 articulating behind a smaller similar one in the left valve. 

 An anterior and posterior la,teral ■f'^^o^''''' ^'r' p^rl,-'^\ v^ive." (From 

 diagnosis of ITeaerom;:a ) Oahh, 1873. 



lype lo oalit^' . - .J ant o nomin go . 



Shell small, thin, elong'ated, subquadrate, decidedly inequi- 

 lateral, being much produced anteriorly; the lorig antero-dorsal 



