October, 1846.] 109 



Professor Johnson read an extract of a letter from Judge 

 Tremper, in continuation of his observations on the tempera- 

 ture and evaporation of Seneca Lake ; also some remarks on 

 the increased rapidity of evaporation from the earth, when 

 the herbage is closely cropped, as in grazing and pasture 

 fields, and the causes thereof. 



Dr. Dickeson stated, that having noticed some tracks re- 

 sembling Ornithichnites, -which were produced by the Alliga- 

 tor, he was induced to cause some tracks to be made in clay 

 by that animal, several of which impressions he exhibited. 

 He also mentioned that tracks of other animals had been re- 

 peatedly noticed by him, which he thought closely resembled 

 the so-called bird tracks of the sandstone slab this evening 

 presented to the Society. 



Dr. Dickeson also made some interesting observations in 

 relation to the habits of the Alligator. 



Professor Johnson offered some remarks on Drift : He re- 

 marked that in the vicinity of St. John's, N. B., he had met 

 with some well marked examples of diluvial action, as evin- 

 ced by scratches on the rocks at great depth. In some cases 

 the grooves were to be found well marked on the side of the 

 rock, while on the other no such action was manifest ; but 

 boulders not in situ were deposited there, as if from the action 

 of a current in a direction from the grooved to the unaffected 

 side of the rock. These boulders also exhibited grooves on 

 their surface. 



Stated Meeting, October 20, 1846. 

 Vice President Wetherill in the Chair. 



DONATIONS TO MUSEUM. 



Dr. Morton deposited six embalmed heads of ancient Egypt- 

 ians, presented to him by A. C. Harris, Esq. 



Dr. Dickeson deposited a very extensive collection of speci- 

 mens in fossil zoology, comparative anatomy, Indian relics, 

 &c, obtained from the Natchez bluffs, the southern lakes 

 and rivers, the aboriginal mounds, &c. 



