1898.] NATURAL SCIENCES OF PHILADELPHIA. 189 



Hab. — The Mesilla Valley of New Mexico, near the Rio Grande, 

 alt. about 3,800 ft. 



The type specimen was shot in the grass on the shore of Arm- 

 strong's Lake, Mesilla, Feb. 1, 1898, by Mr. A. C. Tyson. It is an 

 old male ; the teeth are somewhat worn and one or two are gone. 

 It had eaten some small rodent, which from the foot found in the 

 stomach seems to be Onychomys arcticeps Rhoads. A second speci- 

 men, also a male, was given to us by Mr. C. Barnes, who obtained 

 it from Mr. J. J. Roese. It was killed by a dog in Mesilla Park, 

 and was, unfortunately, much decomposed when it reached our 

 hands. It agrees with the typical specimen, except that the throat 

 is whiter and there is a little more white on the upper lip. Mr. 

 Roese reports that he recently saw four specimens together in a 

 road, early in the morning ; this, with the development of the sex- 

 ual organs, leads us to believe that this (beginning of February and 

 end of January) is the mating season. 



A specimen without any history, in alcohol, is in the collection of 

 the New Mexico Agricultural College. It approaches true frenatus 

 more than our examples, having a spot behind the angle of the 

 mouth, and the white median patch of the head confluent only on one 

 side with the lateral band. The discovery of P. frenatus neomexi- 

 canus extends the range of the frenatus series many hundreds of miles 

 to the north, and into the Upper Sonoran Zone. One of us, after 

 reading Dr. Merriam's account of the North American weasels, 

 prophesied that there would be a new type found in the Mesilla 

 Valley, and such proves to be the case, the characters of our ani- 

 mal, while surely of no more than subspecific value, being quite 

 distinct. 



