44 



LEA, ISAAC, LL.D.- (Continued.) 



Description of a new species of Helix from California, and a 

 new Characteristic Form of certain American Colimacere. (Read 

 March 5th, 1852.) 



Vol. x, p. 303. 1853. 



NOTE. It will be seen that the Date uf Heading of many of Mr. Lea's Papers preceded by several 

 years, that on the Title-page of the Volume in which they were issued. The Transactions were pub- 

 lished in Parts, but afford no internal evidence of the date of their issue, which has unfortunately 

 resulted in much uncertainty in regard to the priority of many of the specific names. Mr. Lea lias 

 given in the Proceedings of the Academy of Natural Sciences. Vol. vii, p 236, a list of dates of publica- 

 tion, which I have deemed it important to insert here. (See Refernn-rs in Parenthesis.) I have al>o 

 given the date on which some of the articles were issued in the Proceedings of the Philosophical 

 Society. Mr. Lea claims that the date of publication of a paper, is that on ir/u'<:h it is T ad. 



IN PROCEEDINGS OF THE ACADEMY OF NATURAL SCIENCES, PHILAIH-L 



PIIIA. 



Including the principal remarks made l>ij Mr. Lea, before the Society '. 



Letter from Mr. Lea, respecting change of orthography in spe- 

 cific names of Unionidrc. Dated October 8th, 1842. (Read No- 

 vember 1st, 1842.) 



Vol. i, No. 2021, p. 215. December, 1842. 



On the Genus Acostrca, D'ORBIGNY. (Communicated October 

 21st, 1851.) 



Vol. v, No. 11, p. 277. October, 1851. 



Eemarks on the Periodicity of the Family Unionidse. (March 

 23d, 1852.) 



Vol. vi, No. 2, p. 54. April, 1852. 



Description of a new species of Symphynote Unio. (Read 

 March 9th, 1852.) 



Vol, vi, No. 2, p. 54. April, 1852. 



Remarks on the Classification of the Naiades by their Anato- 

 tomical Differences. (April 6th, 1852.) 



Vol. vi, No. 2, p. 57. April, 1852. 



Notice of the Mya Nodulosa. WOOD. (June 14th.) 



Vol. vi, No. 9, p. 368. June, 1853. 



Letter to Dr. Leidy, on Castalia Sulcata and other Naiades. 

 (Read August 2d.) 



Vol. vi, No. 10, p. 376. August, 1853. 



