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sua! form in living species. The abdominal anatomy is very- 

 peculiar. On first opening the abdominal cavity there seem to 

 be no organs in it. They are found closely attached to the back 

 bone, and occupy a very small space. Mr. Ayres proposed to 

 call the Dew species, P. Pahnas. 



Mr. Ayres also stated, that he had found Cotlus variabilis to be 

 a very common species along the shores of Massachusetts Bay. 

 It had hitherto been considered a rare species and had not been 

 found north of Cape Cod. 



With reference to the number of species conforming to 

 the fossil types found in North America, Prof. Agassiz said 

 that he had made out ten distinct species belonging to the 

 genus Lepisosteus ; five being of the pointed-nosed, and 

 five of the short-nosed variety. These specimens had been 

 brought from various localities, and the distinctions of some 

 of the species, although constant and sufficiently well 

 marked, are so slight that they would probably have escaped 

 detection, had not specimens been carefully compared with 

 each other side by side. An examination of the young of 

 the various species at different stages of growth shows an 

 interesting conformity with the fossil gradations. 



Dr. Wyman exhibited a canine tooth of the Engeena, 

 Troglodytes gorilla Savage, which had been presented to 

 him by Dr. Savage, but which he had not been able in the 

 absence of perfect specimens to identify till recently. 



The whole length of the tooth was 2.8 inches, the crown 

 measuring 1.3 ; its breadth was 1.0, and its thickness 0.7^. It is 

 slightly recurved, its posterior edge trenchant, and its inner face 

 impressed with two deep grooves, leaving a prominent rounded 

 ridge between them. 



Dr. Wyman also gave some account of certain geological 

 appearances which he had recently noticed on the coast of 

 Labrador. 



Along the whole shore from the S. E. corner at Wapitiguan 

 to Green Bay, in lat. 52° N., boulders exist in great numbers, 



