AND AVES OF NORTH AMERICA. 



191 



part of the month of April, 1860. They were found on the (ami of Geo. W. Crawford, at a place called Nut Swamp, 

 three miles South of Middletown, Monmouth County, N. J. They were first discovered on opening a ditch through 

 :i meadow in Nut Swamp; (}. W. Crawford being an Intelligent farmer, took immediate measures to prevent their 

 disturbance or injury, by having them protected until Ik- could Inform 1'. R. Brinokerhoff. 



Accordingly, on Hie last week of April, I'. K. HrinckerholV succeeded in obtaining from this locality the portions 

 of bones described. 



They were all found at a, depth of about four feet below the surface, arid within an area of a few square feet. 

 The hones were imbedded iii wet marl, which contained an abundance of most of the fossils peculiar to the formation 

 as Gryphrea, Exogyra, Terebratula, Belemnites, &o. Near this spot, about fifteen years ago, considerable portions 

 of the bones, but more particularly the vertebrse of the Mosasaurus, were (bund by J. M. Smil h and Lyell Conover. 



The portions round were so detached and diffused, as to afford no hope of obtaining much more of the skeleton 

 without very extensive arid expensive excavations, arid it was with extreme difficulty that P. K. Brinckerhoff, by the 

 aid of one or two men, and by one-and-a-half days' labor, succeeded in procuring the present specimens. There was 

 a constant influx of water into the trenches, and the bones were; very fragile. 



The bones obtained, consist of large portions of the inferior mamillaries, with twenty, more or less, perfect speci- 

 mens of full grown teeth, and several surcession;il teeth,— with a posterior dorsal vertebra. 



Drawings were made directly from the specimens. 



The largest fragment found is a- porti f the left inferior maxilla,. It measures twenty and three-fourths inches 



in length; at the broadest extremity it is about seven inches deep, at the small extremity it is live inches; f per 



or alveolar portion of the jaw is generally al t three and one-quarter inches thick; the lower margin is quite uni 



formly two Inches thick. This mass was considerably fractured in removing it from its bed, as is seen in the plate. 



It contains the roots of three teeth, two of which have most or their enamelled crowns attached. The space be- 

 tween the first and second tooth is three inches. The space between the second and third teeth is two and three- 

 fourths inches. 



The roots of all the teeth are somewhal compressed laterally; the longest diameter of the root of the first tooth 

 is two inches; of the second, two and one-fourth; of the third, two inches. 



The lateral plates of the dentary bone, come in contact a I'ew inches behind the first tooth. 



In another fragment of the jaw, containing five or six teeth, we find the roots placed in actual contaot throughout; 

 and knowing the law of their arrangement, we can readily estimate the length of the jaw. 



The combined length of all of the fragments collected of the lower jaw, measures four feet, and includes fourteen 

 teeth, which is the full number said to belong to cadi side in M. giganteus. The Series completed would no doubt 



contain eighteen teeth. As the ooronoid anil angular processes and the distal extremity ai it included in the above 



measurements, it would be sale to calculate the lower jaw of this specimen to have been six feet and a half lonir The 

 cranium measured nearly the same, and would indicate a larger animal than any Mosasaurus yet discovered. 



The greater portion of tin. cor >id element of the left inferior maxilla, is nine inches iii length; in the broadest 



part it measures four and three-fourths inches in width. The border is concave ami regularly rounded. This border 

 is quite uniformly two inches thick, while the remaining portion of the fragment is thinner. Another portion of I he 

 left lower jaw contains the roots of three teeth placed in contiguity. The crowns or apices of the teeth have been 

 broken away. This fragment is seven inches long, lour and one-quarter inches deep, and three and one-quarter thiok. 



Three large foramina are seen on the external surface, which communicate with the dental o 1 



This portion of the jaw is well preserved, and like all the fragments found, is entirely black, a xtremely heavy; 



the high specific gravity as well as the color, is due to their impregnation with iron; the pulp cavities ,.r the teeth, as 

 well as the concentric lamina- of the apices, are incrusted with deposit of exceedingly minute crystals of iron pyrites. 



In other portions of the bones a, deposit of vivianitc is occasionally seen. 



In the teeth belonging to this species of Mosasaunis, tin; root is large, the lower extremity inclining backwards' 

 il oontains a minute cavity, being nearly solid, and apparently composed Of Simple osseous tissue. The apex or crown 

 of tin; tooth arises from a, somewhat conical base, which corresponds with the margin of the alveolar cavil y; it tapers 



rapidly to a point; the teeth are recurved and divided into two faces, one looking forwards and mil wards, the other 



presenting backward and inward; the dividing line between the anterior and posterior laces is very distinct, consist 



