NORTH AMERICAN CONCHOLOGY. 433 



220 Anodonta pavonia. 

 220 fluviatilis? 



220 Cyclas similis. 

 220 orbiculata. 



220 dubia. 



Lea. — Observations on the genus Unio, &c. : by Isaac Lea, 

 LL. D., President of the Academy of [Natural Sciences of 

 Philadelphia, &c. 



[Under this title are collected in seven volumes all the descriptions of 

 Mollusca by this author. The original papers were published in the 

 Transactions of the American Philosophical Society, and the Journal of 

 the Academy of Natural Sciences of Philadelphia (new series.) Short 

 diagnoses were also published in the Proceedings of the same Societies. 

 In the following list the numerous foreign species are omitted. As great 

 confusion has arisen regarding the synonymy of the American Naiades, 

 owing principally to questions of priority of publication, I have given the 

 dates of the various papers of Mr. Lea as carefully as possible. In the 

 earlier volumes of the Philosophical Society many of Mr. Lea's papers 

 were published anterior to the completion of the whole volume, but, as 

 no separate dates are given, I am unable to do justice to Mr. Lea. I know 

 of no other rule than to take the date of the title page of the complete vo- 

 lume, unless some other date is given to the separate parts, or with the 

 signatures of the printers. 



Any one desiring further information regarding the actual printing of 

 the various papers is referred to Mr. Lea's "Rectification," in the Proceed- 

 ings of the Philadelphia Academy. 



Reference is given to the Transactions of the Philosophical Society and 

 Journal of the Academy, as well as to the volumes of the "Observations," 

 the numbering of the plates being the same in each. — W. G. B.] 



Trans. Obs. 



Vol. iii, 1830. 



K... 



Pa. PI. Fig. V. Pa. Name. Locality. 



259 i 1 Lea. — Descriptions of six new species of the genus 



Unio, embracing the anatomy of the oviduct of 

 one of them, together with some Anatomical 

 Observations on the Genus. (From Trans. Am. 

 Phil. Soc. (n. s.), vol. iii, p. 259. Date of title, 

 1830.) 



28 



