191 1-] THE ALLIGATOR SNAPPER FROM TEXAS. 453 



formed the present writer that there occur along the Brazos River 

 three principal terraces. The oldest and highest of these, the 

 Hidalgo Falls terrace, lies at a height of lOO or more feet above the 

 present water line of the river. In the materials of this terrace 

 have been found remains of Maiiiiiiiit, Elcphas, Mcgalonyx, Eqiius, 

 etc. About 75 feet below this terrace is found another, the Port 

 Hudson, whose thickness is from 20 to 30 feet. The upper terrace 

 is regarded as older Pleistocene; the Port Hudson, as newer 

 Pleistocene. At a level some 15 to 20 feet below that of the Port 

 Hudson, is a terrace which Professor Deussen considers as of 

 early Recent time. It constitutes the real " bottom lands " of the 

 Brazos and is subject to overflow. 



It is very probable that the remains described here were derived 

 from the lowest and youngest terrace and that the individual lived 

 at some time about the beginning of the Recent epoch. The species 

 probably lives today in the Brazos River. 



The skull (plates X\TII and XIX) lacks the lower jaw, a part 

 of the temporal roof of the left side, most of the occipital condyle, 

 and the hinder part of the supraoccipital process. A close exami- 

 nation reveals no characters by which it can be distinguished spe- 

 cifically from the alligator snapper. The profile (PI. XIX, Fig. 2) 

 is much less concave than in most specimens of the species collected 

 in the rivers of the Southern States ; but there is in the United States 

 National Museum a skull of considerable size, no. 3769, from 

 IMississippi, which presents no greater concavity than does the 

 Brazos River specimen. There are two other skulls, the one con- 

 siderably larger than the skull from Mississippi, the other con- 

 siderably smaller, both of which are much more concave than the 

 specimen from Mississippi. Hence, the amount of concavity seems 

 not to depend on youth or old age. 



The skull of the fossil is, relative to the length, slightly both 

 broader and higher than are two skulls with which it is compared, 

 as is here shown : 



Snout to 

 Specimen. condyle. Width. Height. 



Brazos River skull i 1.19 -84 



No. 3769 U. S. N. M., from Mississippi I 1.14 78 



No. 3444 U. S. N. M., from Red R., Ark i 1.08 .74 



