364 



through the umbilicus. There was but one amnios. This mon- 

 ster belonged to the class of Janiceps, with inferior duplicates, the 

 opening on the occiput being the result of the union of two exter- 

 nal ears. 



Prof. Agassiz remarked, that the inferences drawn from these 

 anatomical relations by the President were peculiarly interesting, 

 having a paleontological as well as physiological bearing, the 

 family of pachyderms being geologically the next in age to the 

 marsupials. He believed we must be prepared to find every 

 possible grade in pachyderms, and still more loose connections, 

 bringing the marsupials nearer the ordinary mammalia than they 

 have hitherto been ranked. 



Prof. Agassiz gave an account of his recent visit to the reefs 

 of Florida and his explorations of coralline growths. He esti- 

 mated the rate of coral growth to be only a few inches in a cen- 

 tury, a tenth or twelfth part less than was formerly supposed ; 

 and, supposing the reef rises from a depth of twelve fathoms, he 

 would calculate its age, upon arrival at the surface of the water, 

 to be about twenty-five thousand years, and the total age of the 

 four distinct concentric reefs of the southern extremity of the 

 peninsula, to be one hundred thousand years. Prof. Agassiz in 

 his remarks presented evidence that Millepora is not a Polyp but 

 a Hydroid. 



Prof. Wm. B. Rogei's said that the physical conditions could 

 not have differed much in that region a hundred thousand years 

 ago from what they now are, and consequently that such a cal- 

 culation could reasonably be made upon the data accumulated by 

 Prof. Agassiz. 



Dr. Weinland called attention to a fact recently observed by 

 him in Hayti, which seems to involve a more rapid growth of 

 some kinds of corals, than is generally assumed for this class of 

 animals. In a small coral basin, between the town of Corail and 

 the island Caymites, which is never disturbed by vessels, the 

 water being there much too shallow, he saw several branches of 

 the large Madrepora alcicornis projecting above the surface of the 

 water from three to five inches. These branches were dead, for 

 corals always die soon after exposure to the air, while the rest 

 of the stock, as far as it was under water, was in full life. This 

 observation was made in the month of June. The question uatu- 



