﻿6o I.AMPSn.TS 



vSubjjcnus KuRVNiA Rafincsc|nc. 1820. 



f.tiryinn Rai-inksouf.. Ann. (un. Sci. Phys. llrux.. 1820, p. 



297. — Ortmann, Ann. Carnegie Mus., \'III, 1912. p. 336. 



Shell oval to oblong; beak sculpture delicate, doubly looped; 

 mantle double edged and often toothed below ; that of the 

 female sometimes developed into a thickened fjaj) at the post- 

 base. 



Type, Unio recta Lamarck. 



Ortmann gives this generic rank with Micromya and Carnn- 

 cuJina as subgenera. A number of the species that I have in- 

 cluded in Eiirynia^ he considers to belong to his restricted genus 

 Lompsilis and to Ncphronmos. T have indicated in the syn- 

 onymy the several species that he refers to Burynia and A''^- 

 phronaias. 



Group of l,arnpsUis luteola. 



Shell inflated, shining, generally rayed ; beak sculpture often 

 broken, with the posterior loop open behind ; pseudocardinals 

 rather small, compressed, smooth inside, and often curved 

 slightly upward. Female shell having a strongly-developed, 

 rounded marsupial swelling. 



Lampsius luteola (Lamarck). 



Shell oblong, solid, subinflated or inflated, rather higher be- 

 hind with moderately full beaks ; beak sculpture consisting of 

 exceedingly fine, doubly-looped ridges, the hinder loops which 

 are sometimes turned up behind and sometimes open ; rarely 

 the sculpture is a little corrugated or broken ; surface with 

 somewhat irregidar growth lines, sometimes slightly concen- 

 trically sculptured, the rest periods few and usually well 

 marked ; epidermis smooth and shining, generally straw-col- 

 ored, yellowish or greenish-Aellow, often becoming brown in 

 old shells, and normally exhibiting bright rays throughout, 

 which may be narrow or wide ; ligament long, sometimes show- 

 ing in a narrow lunule in front of the beaks ; kft valve with 

 two pseudocardinals, which are usually a little compressed, 

 the hinder under the beak, the anterior higher and larger, and 

 two long, rather near laterals, the hinge plate much narrowed 



