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Descriptions of two new species of ANODONTJE, from Arctic America. 



BY ISAAC LEA. 



(Read February 12, 1S61.) 



Anodonta Kennicottii. — Testa laevi, elliptica subinfiata, inaiquilaterali, pos- 

 tice obtuse biangulata, antice rotunda ; valvulis subtenuibus ; natibus promi- 

 nentibus, acuminatis, ad apices granulatis ; epidermide pallido-lutea usque 

 tenebroso-fusca, eradiata ; margarita caeruleo-alba et iridescente. 



Hab. — Great Slave Lake at Fort Rae, and north end of Lake Winnipeg. 

 Arctic America. K. Kennicott. 



An'odosta Sihpsoniana. — Testa, la?vi, elliptica, subcompressa, elongato-len- 

 ticnlari, postice obtuse angulata, antice rotunda ; valvulis tenuibus ; natibus 

 prominulis, ad apices undulatis ; epidermide tenebroso-fusca, eradiata ; marga- 

 rita casraleo-alba et iridescente. 



Hab. — Fort Rae, Great Slave Lake, Arctic America. R. Kennicott. 



Descriptions of New Species of SCHIZOSTOMA, ANCULOSA and LITHASIA. 

 BY ISAAC LEA. 



(Read February 19th, 1861.) 



Schizostoma Spillmasii. — Testa striata, subcylindracea, subcrassa, luteo-fus- 

 ca, imperforate ; spira obtusa, conoidea ; suturis impressis j anfractibus senis, 

 valde vittatis, planulatis, ultimo grandi ; fissura obliqua. subbrevique ; aper- 

 tura grandi, ovata, intus vittata, ad basim obtuse angulata ; columella alba, 

 superne incrassata ; labro-acuto sinuatoque. 



Hab. — Coosa River, Alabama. Dr. Sbowalter. 



I 



Ancclosa tcbbinata. — Testa laevi, subrotunda, crassa, ponderosa, tenebroso- 



cornea, trivittata ; spira. obtusa, vix exerta ; suturis valde impressis ; anfracti- 

 bus quaternis, ultimo pergrandi ; apertura magna, ovata, intus albida, trivitta- 

 ta, ad basim recurvata ; columella incnrva, impressa ; labro acuto, expanso, 

 sinuato. 



Hab. — North Alabama. Prof. M. Tuomey and Dr. Lewis. Tuscaloosa, Dr. 

 Budd. 



Ancclosa Lewisii. — Testa laevi, elliptica, subcrassa, subinfiata, luteo-cornea ; 

 spina obtusa, vix exerts, acuminata ; suturis vix impressis ; anfractibus quinis. 

 ultimo pergrandi ; apertura magna, regulariter ovata, intus albida ; collumella 

 incurva, snperne et inferne paulisper incrassata ; labro acuto, subexpanso. 

 paulisper sinuato. 



Hab. — Tennessee. James Lewis, if. D. 



