also sometimes the case with the cavity of the beaks. Mr. Lea did not believe 

 the color arose, as some persons supposed, from the structure of the surface of 

 the nacre dividing the rays of light by thin laminations. This division of 

 color was exhibited in almost every species, and is what naturalists call the 

 " pearly hue," oftentimes of great beauty, but quite a different matter from 

 the pink, purple and salmon color of the mass of the carbonate of lime com- 

 posing the substance of the valves. 



Descriptions of Four New Species of MELANIDJE of the United States. 

 BY ISAAC LEA. 



(Read March 20th, I860.) 



Schizochilus Showalteeii. — Testa transverse costala, subcylindraec-a, 

 crassu, castanea, minute striata ; spira. elevata ; suturis impressis ; anfractibiis 

 subplanulatis ; fissura submagna, profunda; apertura subparva, elliptic;!, intus 

 vittata.; columella subcrassa; labro paulisper crenulato. 



Hab. — Coosa river, Uniontown, Alabama. E. R. Showalter, M. D. 



Anculosa Showalterii. — Testa valde costata, suborbiculaii, crassa, tenebroso- 

 fusca, nigricante, exilissime striata ; spira brevissima ; suturis valde impressis ; 

 anfractibiis inflatis, septenis transversis costis indutis ; apertura magna, sub- 

 rotunda, superne subangulala, interne tenebroso-vittata ; columella crassa. 

 planulata, tenebroso-fusca: labro valde extenso et valde crenulato. 



Hab. — Coosa river, Uniontown, Alabama. E. R. Showalter, M. D. 



Melania cbenatella. — Testa, transverse striata, turrito-subulata, subcostata, 

 paulisper plicata, subtenui, tenebroso-fusca, nigricante ; spira eleval a, ad apices 

 r-rebre plicata ; suturis valde impressis ; anfractibus septenis, planulatis, trans- 

 versis costis indutis; apertura parva, elliptica, intus vittata; columella 

 albida, incurvata ; labro subcontracto et valde crenulato. 



Hab. — Coosa river, Uniontown, Alabama. E. R. Showalter, M. D. 



Melania Newbereti. — Testa la?vi, ovato-conica, subtenui, tenebroso-fusca, 

 trivittata, inferne suturis lutea; spira subelevata; suturis valde impressis; 

 anfractibus senis, inflatis; apertura parviuscula, ovato-rotundata, intus albida 

 et vittata ; columella albida, incurvata; labro inflato. 



Hab. — Upper des Chutes river, Oregon Territory. J. S. Newberry, M. D. 



