348 



4. Rangia Lecontei, Conrad. Proc. Ac. N. S. Phil. 232, 1860. 



Gnathodon Lecojitei, CoDrad. II. Ac. N. S. Phil. 1853. 

 Hab. N. America. 



5. Eangia mendica, Gould. Conrad, Proc. Ac. N. S. Phil. 



232, 1860. 



Mactra mendica, Gould. Proc. Bost. Soc. N. H. iv. 88, 1851. 

 Gnathodon trigonum, Petit. II. Conch, iv. 84, 1853. 

 Gnathodon mendica, Gould. Proc. Zool. xxiv. 200, 1856. 

 Rangia trigona^ Petit. Adams, Pec. Gen. ii. 380, 1858. Hab. 

 N. America. 



6. Pangia minor, Conrad. Proc. Ac. N. S. Phil. 232, 1860. 



Gnathodon minor, Conrad. Foss. Test. form. 69, pi. 39, f. 6. 

 Hab. N. America. 



7. Pangia parva. Petit. Adams, Pec. Gen. ii. 380, 1858. 



Conrad, Proc. Ac. N. S. Phil. 232, 1860. 



Gnathodon parvum, Petit. II. Conch, iv. 358, pi. 13, f. 9, 10, 

 1853. Hab. New Holland. 



8. Pangia rostrata. Petit. Adams, Pec. Gen. ii. 380, 1858. 



Gnathodon rostratum, Petit. II. Conch, iv. 84, 1853. 



Rangia Jlexuosa, Conrad. Proc. Ac. N. S. Phil. 232, 1860. 

 Hab. N. America. 



Rangia trigona, Petit. Adams, Pec. Gen. ii. 380, 1858, is Ran- 

 gia mendica, Gould. 



While preparing this paper, there appeared in the June num- 

 ber of the Proceedings of the Academy of Natural Sciences of 

 Philadelphia Mr. Conrad's Synopsis of the genus Rangia. It 

 will be seen, however, that the views here taken are not always 

 the same as those of Mr. Conrad. 



Dr. A. A. Hayes exhibited a very fusible white mineral 

 from Lake Superior, containing boracic acid ; it was a 

 silicate and borate of lime, and was obtained from the 

 region of the Minnesota copper mine. 



