MAMMALS SOR10INAE SOBEX HOYI. 



33 



skull. The soles have the large tubercles of S. platyrhinus, but the three central toes are less 

 elongated,, so that the first and fifth claws reach a little beyond the penultimate articulation of 

 the adjacent toes instead of falling short, as in the allied S. personatus and 8. cooperi. The 

 tail is about as long or longer than the body, exclusive of the head ; the vertebra^ as well as 

 the tail itself, considerably shorter than in S. platyrhinus. It is well covered with hair, and 

 tipped with a conspicuous pencil. 



The upper parts strongly resemble those of S. cooperi and S. personatus, being of an olive 

 chestnut brown ; beneath, of a dull rusty white ; the tail beneath and the feet a little paler. 

 There is a decided hoariness on the back and sides, however, varying the reddish brown con 

 siderably, and caused by a greyish tinge to the hairs near the tip. 



The skull is considerably attenuated anteriorly, and the dental formula, \ -f- ^ -f- ^ = 30. 

 The teeth are large ; the anterior incisor well developed, with a large basal hook, as large and 

 coming down as far as the first two lateral teeth. These are of equal size and twice as large as 

 the third, which comes up close to the first molar. The fourth lateral tooth is very small, and 

 only visible from inside. The lower anterior incisor is large, and has two large lobed 

 dentations. Its posterior extremity reaches to the first molar. The tips of the teeth are all 

 colored, to a considerable degree, of a rather dark chestnut. 



Measurements. 



This species bears a close resemblance to S. cooperi and personatus, although readily distin 

 guishable by several excellent characters. The skull, although slender anteriorly, is decidedly 

 shorter, owing to the fact of there being one lateral tooth less and no interval in front of the 

 first molar. The palate is considerably shorter. The teeth are still larger ; the anterior incisor 

 nearly twice as large ; the lateral teeth narrow and descending more ; the molars broader. The 

 lower anterior incisor has but two dentations, instead of three. The teeth, generally, besides 

 being larger, are more extensively and deeply colored than in the above mentioned species. The 

 tail is about as large as that of S. personatus considerably shorter than in S. cooperi. The 

 feet, especially the hinder, are, however, very appreciably shorter ; and the three central toes 

 projects less beyond the lateral. The colors are much the same, except that there is rather 

 more hoariness in the present species. (The above comparison with S. cooperi has been made 

 chiefly with a specimen from the same locality, viz : Racine, Wisconsin.) 



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