MUSEUM OF COMPARATIVE ZOOLOGY. 187 



first accompanied by a plate giving a life-size figure of the animal, with numer- 

 ous details, including the skull and dentition. Dr. Barrocta alludes especially 

 to its supposed medicinal qualities, to the use of its flesh as food by the poorer 

 classes, and to the daily sale of the animals in the market. Duges states that 

 they are readily domesticated and form agreeable pets. 



19. Dipodomys phillipsi, Gray. KANGAROO-RAT. 



Nine specimens, San Luis Potosi, September, October, March, and May, in- 

 cluding adults of both sexes and half-grown young. In point of coloration 

 they present great uniformity, the young exactly agreeing in this respect with 

 the adult. 



" Everywhere common. Very troublesome in the cornfields. NocturnaL 

 Obtained with difficulty and only by digging them out of their burrows." 



20. Heteromys longicaudatus ? Gray. MEXICAN HISPID MOUSE. 



Hderomys alleni, Coues, MS. 



Dr. Palmer's collection contains a single specimen of Heteromys, an adult 

 male, taken at the Hacienda Angostura, Rio Verde, February 26, 1878. Dr. 

 Palmer states that it was discovered in a mound in digging for antiquities. 

 Two were seen, but one of them escaped. He believes it to be rare, as it was 

 not recognized by the natives. Appreciating its importance he offered a reward 

 of a dollar apiece for other specimens, but was unable to obtain any more. 



The genus Heteromys has hitherto been known only from Southern Mexico 

 (Oaxaca) and thence southward to Northern South America. Numerous spe- 

 cies have been described, but only four are recognized by Mr. Alston (Biol. 

 Cent. Amer., Mam., pp. 166-168) as valid, and of these two only (H. desma- 

 restianus and H. longicaudatus) are found north of the Isthmus of Panama. The 

 present example differs apparently in important features from either of these, 

 and a detailed description of it is therefore appended. 



" In size and general appearance it greatly resembles Perognathus fasciatus, 

 but is a typical Heteromys ; the upper incisors being smooth while the pelage is 

 mixed with flat grooved spines. Tail vertebrae as long as head and body ; with 

 hairs, half an inch longer. Tail tufted at the end, the lengthened hairs form- 

 ing a crest, as in Perognathus pencillatus. Soles hairy from the heel nearly to 

 the bases of the toes ; but? a slight strip along the heel is naked. A very 

 prominent black tubercle at the base of the inner toe. Under surfaces of the 

 toes naked and scaly. Palms naked from the wrist. Upper surfaces of hands 

 and feet densely hairy. Ears large, orbicular, projecting beyond the fur ; notch 

 bounded behind by a very large flap-like lobe, in front by a slight fold (much 

 as in Perognathus pencillatus). 



" Coloration not unlike that of Perognathus fasciatus, but darker. Under 

 parts pure white. A conspicuous stripe of fawn-color extends the whole length 

 of the head and body, separating the white under parts from the dark upper parts. 

 Nearly the whole fore leg is colored like the upper parts ; this dark color also 

 descending the hind leg and advancing a short distance on the tarsus. The 



