1906.] A lien , Mammals from Western Mexico . 259 



with the length of hind foot and ear correspondingly greater. As 

 the measurements were all taken by the same person the apparent 

 difference in external measurements is probably a valid difference. 

 As the two regions differ somewhat in comparative aridity, the 

 intensity of the black in the Jalisco series as compared with the 

 Sinaloa series may be only in part due to the season of capture. 



Two old males and one female in the Sinaloa series and two old 

 males of the Jalisco series greatly exceed in size any other specimens 

 of either series, the total length of the former being respectively 738 

 and 769 (c?) and 699 ($), and of the latter 699, 699, about 130 

 and 86 mm. above the next in size. They are apparently simply 

 giants of their race. The skulls of these specimens, while the largest 

 of the series, do not, however, so greatly exceed the next in size. 



None of the specimens of the . Jalisco series seem referable to 

 Conepatus mesoleucus mearnsi, which is supposed to range over the 

 Jalisco tableland. 



It is worthy of note that one of the skulls of this series (No. 25170, 

 9 ad., Arroyo de Plantanar, Feb. 16, 1905) has three supernumerary 

 premolars in the upper jaw, one on the left side, in size and form 

 resembling the anterior upper premolar in Mephitis, and two on the 

 right, much smaller, but the two equalling in bulk the single super- 

 numerary premolar on the left side. The larger of these two is an- 

 terior in position to the other. 



40. Spilogale angustifrons angustifrons Howell. 



Eleven specimens: Arroyo de Plantanar, i specimen, Feb. 17; 

 Garabatos, 4 specimens, March 24-29; Estancia, 5 specimens, Jan. 

 27, Feb. 22, March 8, n, 17; Rio Ameca, i specimen March 20. 



Collector's measurements: 5 males, total length, 378 (352-390); 

 head and body, 236 (222-248); tail vertebrae, 142 (130-152); hind 

 foot without claws, 38 (35-41), with claws, 44; ear from notch, 25.6 

 (22-29): 6 females, 346 (33 6 ~374); 221 (216-241); 125 (114-133); 

 35 (33-38); 23 (22-25). 



One of the females (the skin shows it to have been correctly marked 

 for sex) exceeds in size the average of the males, and one of the males 

 barely exceeds the average for the females. 



Some of the specimens have a broad white band across the thighs, 

 while others are entirely without it ; in still others the band is reduced 

 to a small spot or even to a few white hairs. 



41. Putorius frenatus frenatus (Lichtensteiri) . 

 Two specimens, Artenkiki, Sept. 5, and Los Masos. 



