271 



tendency to nfiolecular change. Pelouze has examined the sub- 

 stance chemically, and found it to be identical in composition 

 with caoutchouc. 



Dr. A. A. Hayes said that Gutta Percha had been thoroughly 

 analyzed in France and its component parts are well known. 

 He had remarked that the molecular change is more readily 

 effected in the light than in the dark. He thought pipes of this 

 material would endure as long as any thing of a vegetable nature 

 could in the soil. 



The President exhibited casts of the Ichthyosaurus, 

 which he had just received from Germany. To this species 

 had been given the name of Ichthyosaurus platyodon, 

 from its flattened teeth. The length of the head is about 

 four feet, equalling that of the largest mastodon. It is 

 supposed that the total length of the individual was about 

 sixty feet. A cast of the head, and of the anterior extremity 

 or paddle, were the parts exhibited and described by the 

 President. 



The Committee appointed by the Council to take into 

 consideration the subject of an expedition to California, for 

 the purpose of collecting objects in the various departments 

 of Natural History, in behalf and at the expense of the 

 Society, reported : — That they had made satisfactory 

 arrangements to that effect with Mr. Emanuel Samuels, the 

 Taxidermist and Janitor of the Society, and that he had 

 already left for California in the prosecution of his object. 

 Mr. Samuels was both willing and anxious to go upon the 

 expedition, not only for the interests of the Society, but to 

 extend his own acquaintance with Natural Science, and 

 earn for himself a wider reputation as collector and taxi- 

 dermist. Animated by this desire, pecuniary profit became 

 an unimportant matter, and he expressed a willingness to 

 go to California, remain there a year and employ all his 

 time in the service of the Society, if it would assume the 

 simple expense of the expedition. Were the Society to 



