S4 Merriam — Bediscoverij of tJic Mexican Kangaroo Rat 



truQ jihlllipsi liy nearly all writers on tlie _uenii8 during tlie past 

 half century. 



In studying a large series of kangaroo rats IVoni Texas, New 

 Mexico, Arizona, and California several years ago I was sur- 

 prised to find that none of them conformed with the original 

 descrijition or with Audubon and Bachman's plate and measure- 

 ments taken from the type specimen in the British Museum. It 

 l)ecame a])parent therefoje that true Dif)ochwys -philli'psi was not 

 represented in the extensive collections examined, and probably 

 was not an inhal)itant of any part of the United States. Elver}^ 

 available means was used to secure specimens from the sup- 

 posed type locality, but without success. Letters were written 

 in both English and Spanish to Mexican officials in Real del 

 Monte describing the animal and offering a reward for a speci- 

 men, and later an experienced mannnal collector was sent to 

 the place, but with no better result. Finally ]Mr. E. AV. Nelson, 

 who has caught hundreds of kangaroo rats in various parts of 

 the United States and Mexico and is thoroughly familiar not 

 only with the habits of the animals but also with the kind of 

 country inhal)ited by them, was requested to visit the region, in 

 connection with his work for the United States Dej^artment of 

 Agriculture. The result is a series of 67 handsomely prepared 

 skins and skulls and several complete skeletons of the long lost 

 Dipodomys philli'psi Hence, after a lapse of more than fifty 

 years, it is now i)ossible for the first time to redefine the 

 type of the genus and to differentiate the species from others 

 with whicli it has been persistent!}^ confounded. Before doing 

 this, however, it seems desirable to put on record with some 

 detail the facts connected with its rediscovery and distribution. 



Notes on a Search for Duplicate Types of Dipodomys phillipsi. 



In response to nry request, Mr. Nelson has contributed the 

 following interesting account of his search for this species : 



'' After securing specimen^; of Dipudumyg phlllipd in the Valley of Mex- 

 ico, at Tlalpam, Ajusco, and Amecanieca in December, 1892, and Februarj^ 

 1893, I finally set out to try and obtain specimens nearer Eeal del Monte, 

 the supposed type locality. A long and careful search in the vicinity of 

 Tula, in Hidalgo, just north of the valley, failed to discover it or any 

 allied species. From that point to Pachuca. along the extreme northern 

 border of the valley, the country presented the same hard, rocky, and 

 unsuitable character found at Tula. Pachuca is situated at the extreme 



