88 Merriam — Bcdiscovcrjj of (Jic Mexican Kangaroo Rat " 



eastern border along the volcanic range from INIonnt Orizaba to the Cofre 

 de Perote, and extending thence west to the eastern base of ■\Ionnt Popo- 

 catapetl, crossing a small corner of Vera Cruz and all of the states of 

 Puebla and Tlaxcala. Since the sandy plain of southern Tlaxcala and 

 central and western Puebla as far as the eastern base of Popocatapetl is 

 a continuation of the same chai'acter of country as that in whicli I have 

 found the species in adjacent parts of these states, I have no doubt that 

 further work will show it to l)e equally connnon in these unexplored dis- 

 tricts. That the species ranges from J'uel)la and Tlaxcala northwesteily 

 toward its reputed type locality in the Sierra de Pachuca is improbable, 

 since a high pine-covered area separates the two districts. 



"The presence of this species in Puebla and Tlaxcala adds considerably 

 to the uncertainty attending the probable source of the type specimen. 

 While Tlalpam was a well-known locality of early days in this countrj-, 

 it is to be taken in consideration that the regular highway (stage road) 

 from Vera Ci'uz to the City of IMexico passed Perote and traversed a hun- 

 dred miles of country where this species is very common. The vertical 

 range of this siiecies lies between 7,400 and 10,000 feet, but by far the 

 greater number of individuals are found between 7,500 and 8,500 feet. 

 Its center of abundance is in southeastern Tlaxcala and adjacent parts of 

 eastern Puebla. Its extreme upper range, both at Ajusco and Mount 

 Orizaba, is due to the animals following cleared fields up into the pines 

 from their original lower range on the ])lains." 



ITahlU. 



Res))ecting the habits of Dipodomys j^hUlipsi Mr. Nelson con- 

 tributes the following, which, unless the contrary is stated, re- 

 lates to the neighborhood of Tlalpam : 



"Their little trails were to be seen after a calm night crossing the 

 sand in every direction, forming in many places a perfect network. Each 

 animal occu])ies a burrow having as a rule a single entrance, dug in tiie 

 bare, open field. The holes enter the ground at a slight angle, and each 

 has a shallow trough-like depression leading out from it for a few inches, 

 as is customary with most members of the group. Ordinarih' the trail 

 leaving the burrow forks, forming a Y very close to the entrance, and 

 each branch trail leads away aci'oss the sandy soil to a neighboring hole, or 

 to a distance where it becomes lost among the .scanty lierbage, where the 

 owner finds its forage of seeds and small succulent leaves. Here ami 

 there little cone-shaped pits, an inch or two deep, show where the inhal)- 

 itants have dug up little plants or hidden seeds. 



" When captured the animals frequently had their cheek pouches full 

 of seeds and small green leaves or young plants. Judging from what I noted 

 in this way, it was evident that quite a variety of small plants contribute 

 to their food supply. At the four localities where they were found they 

 were located in old grain fields and their burrows and habits ajipeared to 



