New Species of Quadruped of the Order Rodentia. 386 
The following are the comparative aunenaions of one of the largest 
specimens of both species.* 
Agama Cornura. - Tapayaxin, 
Totallength, ~ 3in.6 eighths. - Total length, 6 in. 
Length of tail, 1 in. 2 eighths. - Length of tail, 2 in. 
Breadth of body, 1 in. - Breadth, varying. 
- Length of longest horn, 4 in. 
The following are the ascertained synonymes of the animal of 
Hernandez, viz. 
Tapayaxin Lacertus orbicularis, Hernandez, Nova Plant. ae. 
Min, Mexicanorem Hist. p. 327, 8328—(see plate.) 
Phrynosoma orbicularis, Weigmann, in Isis, 1828, pp. 8365-368. 
Wagler, Icon. Amph. pl. 23. fig. 1. and Nat. Hist. 
of Amph. p. 146. Graveuhorst, Acta. Acad. Cas. 
Leop. Carol. Nat. Cur. vol. xvi. p. ii. 
Tapaya stiihade, Cuv. Régne animal. ii. p. 
Agama orbicularis, Voigt, Trans. of Cuv. R. A. ‘4. p. 59. 
We have seen a specimen of A. orbicularis in the museum of 
Cincinnati, said to have been obtained from the plains of Missouri. 
If the statement be Seo we shall have four mosses. of Agama in 
the United States, viz.: A. Cornuta, A. Collaris, A. Douglassii ; 
together with the first named species—vid. sims Med. and Phys. 
Researches, for figures of the others. 
Art. XXIV.—Description of a new species of Quadruped, of the 
order Rodentia, inhabiting the United States; by R. Haruay, 
a 7S 
Mus palustris. 
Characters.—Body rather elongated, color above of a ferruginous 
brown ; beneath, grayish white, the hairs being plumbeous at = 
legs seosll tail long: ears half the length of the head. 
“Desorption. —The color above resembling nearly that of the com. 
mon Norway rat; beneath, grayish white ; ears of moderate size, 
anterior borders slightly inverted, sparsely hairy within and without : 
* The specimen figured by Wagler, was rather larger, viz. total length 7 in. ; 
tail 24 in, 
Vou. XXXI.—No. 2. 49 
