4 [Feb. 



birds, and he had also ascertained, that several African species not only devoured 

 insects with eagerness, but also caught them vs'ith great dexterity. A specimen 

 of the Cei-co}}ithecus saher/ts, observed by him, was very I'ond of the common 

 cockroach, and upon being furnished with a daily supply of that insect, actually 

 recovered perfect health alter symptoms of disease had made their appearance. 

 This individual caught cockroaches with surprising adroitness, and when one 

 escaped, he would watch for it to reappear with the patience and quiet of a cat. 



Mr. C. stated as his opinion, that all the African monkeys (and perhaps all 

 others) were insect eaters, and to a person aware of the large number and enor- 

 mous size of many of the species of Coleoptera of Africa, it would appear a reason- 

 able supposition that those insects were eaten by monkeys. 



All monkeys in confinement should be furnished with animal food, either 

 insects, or raw mutton, or beef, cut into tiiin strips resembling worms, which he 

 had found to be the best substitute. 



Mr. C. stated that much of the disease of those animals in captivity, was 

 doubtless to be attributed to the fact, that they were invariably, as far as he had 

 observed, restricted to vegetable food. 



February 8th, 1848. 

 Vice President Morton in the Chair. 



The Chairman read a letter addressed to him by Dr. R. W. Gibbes, 

 dated Columbia, S. C, January 27th, 1848, enclosing another from 

 Prof. Agassiz, addressed to Dr. Gibbes, dated Charleston, December 

 23d, 1847, and coinciding with him in the opinion that the Basilo- 

 saurus of Harlan, or Zeuglodon celoidcs of Owen, is generically dis- 

 tinct from the species described by Dr. Gibbes under the generic name 

 of Dorudon, and published in these Proceedings. The following is a 

 portion of the letter of Professor Agassiz : — 



" I have examined the interesting fossil remains of Cetacea which you left with 

 me yesterday. On close comparison, I have satisfied myself that Basilosaurus 

 or Zeiiglodoii. cetoides, is generically distinct from your second species, which you 

 first described under the generic name of Dorudon. The hollowness of the teeth 

 cannot be indicative of a mere young age of that animal, as the form of the lower 

 jaw is altogether difTerent in the two animals : Zeuglodon having a continuous 

 fissure connecting the alveoli, and another groove along the edge of the jaw-bone, 

 which are wanting in Dorudon. Besides, the posterior branch of the jaw is also 

 different, the two lamcUre of the bone rising to the same height, and much higher 

 in Zeuglodon, than in Dorudon, which has a deep depression upon its external sur- 

 face, owing to the difference in the heiglit of the two laminae. Again, Zeuglodon 

 has deep pits upon the external surface of the lov.-er jaw, shewing that the teeth of 

 the upper jaw left an impression upon the lower, resting upon it, as in the croco- 

 diles of our days, when the mouth is shut. The other portions of the jaws of 

 Dorudon are from the upper jaw, the one with one tooth being from the left side, 

 the other with three teeth being from the right side. I am therefore sorry that 

 you have withdrawn your genus, in deference to the suggestion of Prof. Owen, as 

 he did not insist upon their generic identity, but rather alluded to the close affinity 

 of these remains. 



The isolated tooth, though imperfect, is highly interesting, as indicating a new 

 genus of Sauroid Cetacea, allied to Me^alosaurus by the form of the tooth, but 

 difTering byithe form of its root. I would propose to call it Sauro-cHits G-ihhesii. 

 It will easily be distinnuished from the fang of Dorudon, by its great flatness and 

 acute serrated edge. In the form of these anterior teeth tliere is another generic 

 difference between Zeuglodon and Dorudon, worth mentioning; in the former 

 being blunt and short, whilst Dorudon has them acute and sharp upon the edges. 



1 thank you for the opportunity you have afforded me to examine these highly 



