Observations on a Fossil Jaiv of a species of Gavial, 

 from West Jersey. By J. E. D e k a y. 



Read January, 1833. 



In a paper which I had the honour to lay before the society 

 some time since, the attention of the members was called to 

 some fossil remains from the southern parts of New Jersey. 

 The interest which has been excited, both here and in Europe, 

 on this subject, induces me to submit a few additional observa- 

 tions on some organic remains from the same locality. For the 

 opportunity thus afforded me I have to express my obligations 

 to Lieut. Mather, of the army, who has kindly placed the spe- 

 cimens in my hands for examination. 



A few brief remarks upon the region from whence these and 

 other remains are found in such abundance, may be necessary 

 previous to describing the fossils themselves. 



West Jersey, or that part of the state of New Jersey which 

 lies south of a line drawn from Trenton to Amboy, is composed 

 entirely of sand, passing at some places into gravel. At the 

 Highlands of Navesink, which rise into hills 300 feet high, a 

 rock formation appears, containing fossil shells and Crustacea. 

 This same rock appears on the borders of a stream at Tinton 

 Falls, and from its composition is called ferruginous sandstone. 

 It consists of iron and silex with potash and alumine ; and the 

 same materials, in various proportions, compose those numer- 

 ous local deposits which are found extensively scattered over 

 this whole region. To some of these are applied the name of 

 marie pits, on account of their fertilizing properties ; although 

 totally dissimilar to the marie of Europe ; and, in fact, only 

 acting inechanically, like any other clay, when mixed with a . 

 sandy soil. In these various deposits are found animals of 

 fresh and salt water, of such as were formed to encounter the 



