302 

 XLVIII. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



Jan. 9, — A NOTICE was first read on the discovery of the Basllo- 



1839. -^ saurus and the Batrachiosaurus, by Dr. Harlan. 



The first remains of the Basilosaurus, which came under Dr. 

 Harlan's notice, were a vertebra and some other bones found in the 

 marly banks of Washeta river, Arkansas territory. In the autumn 

 of 1834, he examined another collection discovered in a hard lime- 

 stone in Alabama, and consisting of several enormous vertebrae, a 

 humerus, portions of jaws with teeth, and some other fragments sup- 

 posed to belong to the same animal. In the matrix of the vertebra 

 from the Washeta river was a fossil Corbula, common in the Alabama 

 tertiary deposits, and specimens'of Nautilus, Scutella, and Modiolus of 

 extinct and new species; sharks' teeth have also been found in a similar 

 rock in the vicinity of the locality from which the other collection 

 was procured. Dr. Harlan was originally inclined, from the struc- 

 ture of the teeth, to consider these fossil remains as having belonged 

 to a marine carnivorous animal ; but from an examination of the 

 bones he was induced to conclude, that they were portions of a 

 new genus of Saurians, for which he proposed the name of Basilo- 

 saurus. 



Dr. Harlan then briefly described a portion of an upper jaw of a 

 Saurian discovered by a beaver-trapper, on or near the banks of the 

 Yellowstone river, in the territory of the Missouri, imbedded in a 

 hard l)lue limestone rock. On first inspection Dr. Harlan believed, 

 from the structure of the teeth, the mode of dentition, and the po- 

 sition of the anterior nares, the fragment belonged to an Ichthyo- 

 saurus ; but as it diflPers entirely from that genus in having separate 

 alveoli, and in the form and position of the intermaxillary bones, 

 while it approaches in the latter characters the batrachian reptiles, 

 he has formed for the fossil a new genus designated by the name of 

 Batrachiosaurus. 



A paper was afterwards read, entitled, " Observations on the 

 Teeth of the Zeuglodon, Basilosaurus of Dr. Harlan," by Richard 

 Owen, Esq., F.G.S., Hunterlan Professor in the Royal College of 

 Surgeons, London. 



During the recent discussions respecting the Stonesfield fossil 

 jaws, one of the strongest arguments adduced and reiterated by 

 M. de Blainville and others in support of their saurian nature, was 

 founded on the presumed existence in America of a fossil reptile 

 possessing teeth with double fangs, and called by Dr. Harlan tlie 

 Basilosaurus. To the validity of this argument, Mr. Owen refused 

 to assent, until the teeth of the American fossil had been subjected 

 to a re- examination with an especial view to their alleged mode of 

 implantation in the jaw ; and until they had been submitted to the 



