186 BULLETIN OF THE 



18. Neotoma floridana mexicana (Baird), Allen. Mexican Busu Rat; 

 " Rata del Cajipo." 



Neotoma imxicana, Baird, Proc. Acad. Nat. Sci. Phila., VIL, April, 1855, 333 ; 



Mam. N. Am., 1857, 490 ; U. S. & Mex. Bound. Suiv., II. Pt. 2, 1859, Mam., 



p. 54, PL XXIV. fig. 1, skull. 

 Neotoma micropus, Baiud, Proc. Acad. Nat. Sci. Phila., VIL, April, 1855, 333 ; 



Mam. N. Am., 1857, 492; U. S. & Mex. Bound. Surv., II. Pt. 2, 1859, Mam., 



p. 44. 

 Neotoma floridana, Geoffroy, Zool. Voy. Venus, 1855, 154, PI. XIII. — Coues, 



Mon. N. Am. Roden., 1877, 14 (partim). — Duges, La Frateniidad, I., 1874, 82, 



PL (animal, details of external parts, skull, and dentition). 



A series of eight specimens, two collected in October and tlie remainder in 

 March, at San Luis Potosi, contrast so strongly in color and size with Florida 

 examples of Neotoma that the Mexican form seems eminently worthy of varie- 

 tal recognition. The Mexican specimens are fully one fourth smaller, the tails 

 are much more thickly clothed, and the color is widely different, ^agreeing, 

 however, in every respect with N. mexicana, Baird. The tail is sharjily bicolor, 

 and the feet and the lower surface of the body are snowy white, separated from 

 the mouse-brown of the back by a well-marked band of yellowish-rufous or 

 golden-rust, varying in intensity in different individuals. Two specimens 

 have the dorsal surface strongly ferrugineous throughout, varied of course with 

 black medially, passing into strong reddish brown on the sides, thus in general 

 tint strongly resembling N. ferruginea, for which they were at first mistaken. 

 One is a male, the other a female, and they were taken, respectively, March 10 

 and March 24. Another specimen, a female, taken March 20, presents the 

 opposite extreme of paleness, being gray above, varied with black and faintly 

 tinged on the sides with a pinkish hue. These examples indicate an exceedingly 

 wide range of individual variation in color ; the other specimens, however, are 

 variously intermediate, and form altogether a closely intergrading series. 



"These rats are sold in the markets as food for invalids whose stomachs are 

 unable to retain other food ; as a cure for chronic diarrhoea and dysentery is 

 believed to have few equals. The animals are split open and applied as a 

 poultice to parts affected with pain. The market of San Luis Potosi is never 

 without these rats. They are said to be good eating aside from their as- 

 cribed medicinal virtue. They are very abundant, inhabiting the localities 

 of the magueys or agaves, about the roots of which they live, probably be- 

 cause the thorny nature of the plant prevents rapacious animals from bur- 

 rowing after the rats, or possildy in order to feast upon the roots. They 

 live in the gnnind, and the daily supply seen in the market of San Luis Potosi 

 is obtained by digging them out of their burrows. They are known under the 

 name Rata del Canipo." 



Dr. Palmer has kindly called my attention to two papers on this species in 

 " La Fraternidad " * by Don Alfredo Duges and Dr. Gregorio Barrocta, the 



* La Fraternidad — Periodico do, la Sociedad Medica de San Luis Potosi, Tom. I., 

 Entr. No. 6, Junio de 1874, pp. 82-87 y pi. 



