ANODONTA. 



49 



f OVAL. 



An. minima. Pot. 



An. Grateloupiana. Gass. 



An. ovalis. Requien. Pot. 



An. Pupuyi. Ray and Prout. Pup. 



An. arelatensis. Jacq. Pup. 



An. Millettii. Ray and Prout. Pup. 



An. Normandi. Pup. 



An. oblonga. Mill. Pup. 



An. Rayii? Pup. 



An. subponderosa. Pup. 



An. scaldiana. Pup. 



An. Moulinsiana. Pup. 



An. subrhomboidea. Brown. 



An. contorta. Brown. 



An. luxata. Held. Kilst. 



An. callosa. Kilst. 



An. inornata. Kilst. 



An. cariosa. Kiist. 



An. arealis. Kiist. 



An. subluxata. Kiist. 



An. Sondermanii. Kiist. 



An. anserirostris. Kiist. 



An. tenella. Kiist. 



An. tumida? Menke. Kiist. 



An. confervigera. Schluter. 



An. rhomboidea. Schluter. 



Anodontites cygnea.* Poir. 



Anodontites anatina. Poir. 



fOVAL. 



*Oregonensis. Lea. 

 An. cognata. Gould. 



*Pepiniana. Lea. 



*fragilis. Lam. 



*Footiana. Lea. 



uniopsis. Lam. 

 Unio uniopsis. Pesh. 

 Alas, compressa. Par. 



*Chaiziana. 2 Rang. 

 Epigenia decorata. Parr. 



*undulata. Say. Eild. 3 Gould. 

 Adams. Linsl. 

 Anodon rugosus. Swain. 

 Anodonta Pennsylvanica. Lam 

 Unio undulata. Pesh. 

 Alas, marginata. Kiist. 

 Strophitus undulatus. Stimp. 



*Wardiana. Lea. 

 A. virgata. Con. 



*edentula. Lea. BeJcay. 



1 Fide Des Moulins. 



2 M. Rang informed me that this species has the singular power of maintaining its vitality in the desiccated 

 marshes of Africa, through six months of the burning sun of that region ; and that he had a specimen sent to him 

 in Paris, which was killed nearly thirteen months after it had been taken from its native bed, having occasionally 

 been dipped in water for an hour or two only. He also mentions that the Iridina rubens is found with the Chaiziana 

 in the Senegal, and possesses the same peculiarities of remaining in a state of torpidity during the season of great 

 heat. A specimen, under the name of Chaiziana, sent to Dr. Jay from Europe, and given to me by him, is, I 

 think, a young Iridina rubens. Dr. Vandenbusch, of Bremen, sent me, more recently, a thicker and more inflated 

 specimen under the name Epigenia decorata, of Parreyss and other Vienna naturalists. This appears to me to be 

 the female of the same species. I think it possible that An. Chaiziana, An. Tawaii, and E. decorata may all 

 prove to be identical, varying by geographical position, sexual difference, or age. I have had very strong doubts 

 whether this be not a young Iridina rubens, but the two specimens I have seem to be mature, and Rang describes 

 and figures his Chaiziana without siphons. The lesser of the two anterior cicatrices is smaller in my two spe- 

 cimens, and more elongate, than in rubens. 



3 I doubt very much if Dr. Hildreth had Mr. Say's undulata under his eye when he made his description. 

 The undidata of Say does not exist west of the Alleghany Mountains, and Dr. Hildreth probably had some other 

 species, which, not being figured and the description being imperfect, I cannot make out. This species is said to be 

 found in Oneida Lake and Lake Ghamplain. 



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