87 



September 3, 1851. 

 Dr. Samuel Cabot in the Chair. 



Prof. James Hall, of Albany, and Dr. Josiah C. Nott, of 

 Mobile, present by invitation. 



Dr. Burnett read a paper on the relations of Embryology 

 and Spermatology to classification. The purport of the 

 paper was to show the value of the latter as an element in 

 a perfect system of classification, by exhibiting the distinct- 

 ive forms of the Spermatozoa in the various departments 

 of the animal kingdom. It contained many interesting 

 facts which had come under his observation in the course 

 of his investigations with the microscope during the past 

 two years. 



Dr. Gould exhibited and presented descriptions of a 

 number of California shells, collected by Maj. William 

 Rich and Lieut. Thomas P. Green, United States Navy, 

 some of which had hitherto been considered identical with 

 species on the East coast of the United States. On com- 

 paring the specimens side by side, marked differences were 

 evident, as was pointed out by Dr. Gould, who remarked 

 that he had found similar differences between fossil and 

 recent shells from Carolina, which had heretofore been 

 regarded as the same species. 



Pholas ovoidea. T. ovoidea, solidula, cinerea, postice hian- 

 tissima et epldermide valde prolongata ; margine ventrali antice 

 lamina calcarea clause ; apicibus ad Irientem anteriorem testae 

 posilis ; valvis sulco mediano partitis, portione antico rotundato 

 laminis concentricis radiatim striatis exasperate, portione postico 

 subcylindrico, striis concentricis remotis notato ; apophysi cardi- 

 nali subulato, ad apicem dilatato ; valvis auxiliariis nullis? Long. 

 3; lat. If; alt. 2 poll. Inhabits Monterey. Maj. Rich. 



Remarkable for its short and ovoid form, and its great debis- 



