ON THE ZOOLOGICAL POSITION OF TEXAS. 13 



EEPTILIA. 



CEOCODILIA. 



Alligator mississix^piensis. The western limit of the range of this 

 species has never been fixed, and I used my opportunities to acquire 

 information respecting it in Texas. It is common in the waters of the 

 Guadalui^e drainage, and is occasionally seen in the San Antonio Eiver 

 within the limits of the city of San Antonio. According to Mr. G. W. 

 Marnock it is found in the Kueces, to its sources, and a skull in his 

 possession belonged to an alligator which was killed between that river 

 and the Eio Grande. In his report on the Herpetology of the United 

 States and Mexican Boundary, Professor Baird records a specimen from 

 Brownsville, on the Eio Grande. 



TESTUDINATA. 



Testudo herlandieri Agass. I obtained a specimen of this land tortoise, 

 collected by Mr. Marnock in the southwestern part of the State, where, 

 according to that gentleman, it is common. He has also found it near 

 San Antonio. I did not meet with it on the first plateau. 



Cistudo ornata Agass. From near Dallas, Boll. 



Pseudemys mobilensis Holbr. This species, remarkable for the long 

 tooth-like processes of its alveolar surfaces, is not rare in the drainage 

 area of the Guadalupe Eiver. 



Pseudemys elegans Wied. This water-turtle is stated by Agassiz to 

 range over the entire State of Texas. I found it at remote points, i. e., 

 the Upper Trinity Eiver near Fort Worth, and the Helotes Creek, near 

 San Antonio. 



Kinosternum lienrici Leconte. Found by Mr. Marnock on the ti^ibu- 

 taries of the Medina, in the region of San Antonio. I did not see it on 

 the i)lateau. 



Kinosternum pennsylvanicum L. A pair of this species was sent me 

 from near Dallas by Mr. Boll. The male was very active and fierce in 

 confinement, and devoured flesh greedily. 



Aspidonectes cmoryi Agass. Obtained by Mr. Boll, near Dallas, in 

 Korthern Texas, and by Mr. Marnock in Ilelotes Creek, near San An- 

 tonio. I repeatedly saw soft-shell tortoises {Trionychidcv) in the tribu- 

 taries of the Brazos and Guadalupe, in the lowlands and first plateau. 



LACEETILIA. 



Coleonyx variegatus Baird. This very pretty lizard is the only species 

 of the Oecconidce thus far found in Texas. Only two other species of 



