260 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. 



the commission, where the present, the only one observed, appears to 

 be the most characteristic species. Professor Agassiz notices speci- 

 mens from different localities in Minnesota and from the Yellowstone, 

 M here it was also observed by the Prince Maximilian and Mr. J. A. 

 Allen. The former naturalist expresses great doubts respecting the 

 accuracy of Nuttall's statement that it is found in Oregon, as it has 

 never been seen in that Territory by any of the recent explorers, the 

 only true Turtle of the Pacific slopes being the Chelopus marmoratus Bd. 

 & Grd. {Emys nigra of Hallowell). It is, however, a species of wide 

 distribution in the central region, having been observed southward 

 nearly to the Mexican border in Texas. 



The following additional species of this order are indicated by authors 

 as occurring on or near the northern boundary: — 



Genus PSEUDEMYS. Gray. 



PSEUDEMYS ELEGANS. {Maxim.) 



Elegant Terrapin. 



Emys elegans, Maxim. Reise Nord-Amer. i. 1839, 213 (Upper Missouri). — Hayd. Trans. 



Am. Phil. Soc. sii. 1862, 177 (Yellowstone). 

 Trachemya elegans, Agass. Contrib. Nat. Hist. U. S. i. 1857, 435.— Bd. U. S. Max. B. Surv. 



ii. pt. ii. 1859, Eeptiles, 3 (Texas.) 

 Pseudemys elegans, Gray. — Cope, Check List Bat. Eept. N. A. 1875, 53. 

 Emys cumie^-landensis, Holbr. N. Am. Herpet. i. 115, pi. 118 (Tennessee). — DeKay, N. 



Y. Fauna, iii. 1842, 20. 

 Emys holbrookii, Gray, Cat. Brit. Mus. 1844, 23. 

 Emys terrapin, Wailes, Geol. Eep. Mississippi, 1854, p. — (fide Agass.). 



A species originally described from the Upper Missouri by Prinz 

 Maximilian von iJfeu Wied, and subsequently ascertained to occur 

 throughout the Central region, east to the Ohio, and south to Texas. 



Genus CISTUDO. Fleming. 

 CiSTUDO OENATA. Agass. 



Ornate Box-turtle. 



Cistudo ornata, Agassiz, Contrib. Nat. Hist. U. S. i. 18,57, 445, pi. 3, f. 12, 13.— Cope, 

 Check List Bat. and Rep. N. A. 1875, 53. 



The Northwestern type of Cistudo, Professor Agassiz remarked, in 

 proposing C. ornata, is of all the forms the most likely to be distinct, and 

 such has j)roven to be the case. '• It is round, broad, and flat, without 

 keel, even when young, while the young of Cistudo virginea are 

 always strongly keeled." The species is based upon specimens from the 

 Upper Missouri and from Iowa. 



