ANODONTA. 



79 



fOVAL. 



*Chaiziana.' Rang. 



Ejngenia decorata. Parr. 



*uiidulata. Say. Hild.^ Sh. & Eat. 

 Gould. Adams. Linsl. Han. 

 Anodon rugosus. Swain. 

 Anodonta Pennsylvanica. Lam. 

 Unio undulata. Desh. 

 Alas, marginata. Kust. 

 Strophitus undulatus. Stimp. 



Strebellii. Lea. 



*Sliowalterii. Lea. 



*Warcliana. Lea. 

 A. virgata. Con. 



*edentula. Lea. Dehay. Han. 

 Alas, edentula. Say. 

 Alas, rhomhica. Anth. 

 An. areolata. Sivain. Coop. Linsl. 

 An. unadilla. Dehay. 

 Hemiodon areolatus. Swains. 



*pavoiiia. Lea. Dehay. Han. 



OVAL. 



"Weddellii. Hupe. 



obtusula. Hupe. 



lingulata. Hupe. 

 *limrLoica. D^Orh. Han. 

 *HoltorLis. Lea. 



purpurea.' Valen. Han. 



*Ferussaciana. Lea. Dehay. Han. 

 Alas. Ferussaciana. Kilst. 



*Kennerlyi. Lea. 



*inodesta. Lea. 



*denigrata. Lea. 



*oblita. Lea. 



*plicata. Hald. 



*ara;entea. Lea. 



' 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 Ghaiziana in the Senegal, and possesses the same peculiarities of 

 remaining in a state of torpidity during the season of great heat. A specimen, imder the name of Ghaiz- 

 iana, sent to Dr. Jay from Europe, and given to me by him, is, I think, a young Iridina rubens. Dr. 

 Vandembusch, 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. Ghaiziana, 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 Ghaiziana without siphons. The lesser of the two anterior cicatrices is smaller 

 in my two specimens, and more elongate, than in rubens. 



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

 tion. The undulata 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. 

 The species is said to be found in Oneida Lake and Lake Champlain. 



2 Von Martens {Malac. Blatt. 1867) considers the following to be synonjnns: An. Boroughiana, Lea; 

 U. Bengalensis, Lea ; U. verecundus, Gould ; An. subcrassa. Lea ; A7i. tenuis. Lea ; An. crepera, Lea ; 

 An. gracilis, Lea. He is certainly mistaken in most of these at least. 



