30 I.OU/S AGASSIS. [CHAP. xiv. 



resident of that part of the country. We saw the cele- 

 brated New Jersey grecnsand, and collected in it a 

 quantity of sauroid teeth, fragments of vertebras of a 

 crocodilian, Ostira vcsicularis, Tcrcbratula Sayii, Pecten, 

 Area, J/j'(t, etc. Above the greensand and green marls 

 there are yellow sands and yellow calcareous sandstone 

 containing many echinoderms, such as Holastcr, Nnclc- 

 olitcs, Diadona, Hctniastcr, Ccratomns; and many Teredo, 

 Scalaria, and corals; the whole formation belonging 

 to the lower chalk and upper greensand of England. 

 The excursion was very successful, and Agassiz returned 

 to Philadelphia in better health and spirits. 



Dr. Joseph Leidy, so justly celebrated since for his 

 great works on the comparative anatomy of American 

 fossil vertebrates, was then a young student just returned 

 from Paris, where he had followed the lectures and also 

 the private instructions of de Blainville, the successor 

 of Cuvier in the chair of comparative anatomy. Leidy 

 was the naturalist who followed, with the greatest atten- 

 tion and best results, the lectures of Professor Agassiz, 

 and received the most benefit from his presence in 

 Philadelphia. Agassiz was much impressed by his 

 :st manner, and predicted a great future for him if 

 he would devote his life to comparative anatomy. Many 

 were given by Philadelphia society in honour of 

 vas not without regret that on April 1 1 

 he left the city of Penn, returning directly to Cambridge, 

 suming his duties at Harvard University, he de- 

 limself, during the year, to microscopical studies, 

 calcpluc or Mcdnsic of the shores 

 rhich resulted in the publication of 



