260 Dissection of two doubtful reptiles. 



was still so perfect, that I have presented it to the Lyceum. 

 It was recognised as the larva of a species of libellula. 



The pyloric contraction of the stomach was very evident, 

 and an inch below it, the hepatic duct entered the duodenum. 

 The spleen was connected with the left side of the stomach, 

 there were no pancreas. 



The heart was contained in a very large pericardium. It 

 was large, membranous, and irregular ; but the quicksilver 

 with which I attempted to inject it escaped, so that I could 

 not determine its real shape. One vessel alone, I presume 

 the aorta, arose from its right side. The inferior cava en- 

 tered below. From the length of time the animal had been 

 kept in spirits, I could not trace these vessels to my satisfac- 

 tion. Dr. Mitchill, I understand, expects a further supply, 

 when I hope to be more fortunate. 



In the inferior part of the throat the glottis opened. The 

 passage was one eighth of an inch in its antero-posterior 

 diameter, but very narrow. I have passed a thread through 

 it of a red color, so as to mark it, as otherwise it would not 

 be very perceptible. This passage communicated with the 

 lungs, only one of which I could inflate. This lung is a sac 

 about three eighths of an inch in diameter, and four and a half 

 inches long when inflated. 



Here then is an animal furnished with one organ for the in- 

 halation of air, and with another for extricating oxygen from 

 the water, so that it is really and truly amphibious. This 

 anatomical conclusion is confirmed by observation, our learn- 

 ed President, Major Delafield, having frequently seen the 

 Proteus on the shores of the lakes, although the water be its 

 proper element. 



The celebrated Cuvier* admits that animals of this de- 



* See Observations de Zoologie, par Humboldt and Bonpland, Vol. I. 

 p. 93. et seq. Paris. 1811. 



