830 PROCEEDINGS OF THE ACADEMY OP 



the parts are in a normal condition. It is. therefore, greatly to he desired 

 that zoologists in our different zoological districts would give attention to the 

 anatomical structure of the species which inhabit their own districts. Eventually, 

 in this way, there may be built up a correct knowledge of the habits and anatomy 

 of this interesting family, of which we have a somewhat comparatively correct 

 diagnosis of the exo-skeleton. 



Mr. Lea also mentioned that, in connexion with this subject, he had paid 

 much attention to the power of vision in the family Unionidte, since his com- 

 munication on the subject, in February, 1857. He found the following species 

 always to close the anal opening, and to withdraw the papillae of the branchial 

 opening when the light was suddenly intercepted, viz : 



Unio cylindricus, Say. 



Unio rubiginosus, Lea. 



Unio subrotundus, Lea. 



Unio pyramidatus, Lea. 



Unio obscurus, Lea. 



Unio pustulosus, Lea. , 



Unio JEsopus, Green. 



Anodonta imbecilis, Say. 



Dr. J. A. Meigs read some remarks of Mr. Joseph Barnard Davis, 

 reviewing the method of measurement, as a diagnostic means of distin- 

 guishing human races, adopted by Drs. Schertzer and Schwarz, in the 

 circumnavigatory expedition of the Austrian vessel Novara. 



The number of the Proceedings of the Academy for November was 

 laid on the table. 



December loth. 

 Dr. Ruschenberger in the Chair. 



Thirty-three members present. 



A paper was read, entitled, " Reflections upon the nature of the 

 temporary star of the year 1572, an application of the nebular hypothe- 

 sis, by Alexander Wilcocks, M.D.," and was referred to a committee. 



The decease of Dr. H. C. Caldwell, late a member of the Academy, 

 was announced : he died at Lewisburg, Va., Dec. 1st., aged 28 years. 



December 20th. 

 Mr. Lea, President in the Chair. 



Forty-five memhers present. 



Papers were presented for publication in the Journal, entitled, "De- 

 scriptions of New Cretaceous and Eocene Shells of Mississippi and Ala- 

 bama, also, with Notes on Eocene Fossil Shells, by T. A. Conrad." 



" Descriptions of Exotic Unionidae, by Isaac Lea." 



And were referred to a committee. 



The following were presented for publication in the Proceedings : 



a Notice of the Shells collected bv Mr. J. Xantus, at Cape San Lucas, 

 by P. P. Carpenter." 



[Dec. 



