171 



COMPARATIVE MEASUREMENTS IN INCHES. 



Nose to tip of tail 



" " occiput 



" " root of tail 



" " extended hind foot 



" " tip of ear 



" " eye . • 



" " posterior angle of mouth ... 



Length of tail vertebrae 



" " tail to tip 



" , " ear 



" " snout , 



" " whiskers , 



" " leg from knee , 



" " foot 



" " arm from, elbow 



" " hand 



Greatest distance between extended feet . 



•sS 



ic»p. 



O :;3 



3.20 



.75 



2.00 



2 00 



.70 



.30 



.25 



1.15 



1.23 



.25 



.14 



.50 



.80 



.38 



.45 



.23 



2.05 





3.75 



.80 



2.00 



2.62 



.87 



.35 



.23 



1.50 



1.75 



.25 



.15 



.60 



.90 



.45 



.57 



.28 



2.50 





60*% 



.3.15 



.75 



2.00 



2.50 



.85 



.33 



.2-5 



1.10 



1.15 



.30 



.13 



.55 



.80 



.40 



.50 



.26 



2.25 



In color and general appearance, this species resembles S. Cooperi, 

 but is considerably smaller.* The latter has also 32 teeth instead of 

 30 ; its nose is longer and much more attenuated ; its tail is dispro- 

 portionately longer and larger, and its feet and ears are much larger, 

 though of about the same form. 



In proportions, size and form, S. personaius, of the South, resem- 

 bles it still more closely, but its color is a light chestnut brown. It 

 also has 32 teeth; a shorter tail, though a somewhat larger species in 

 other respects ; and the ears are much longer and less rounded, and 

 have much more hair on the inside of the concha. The specimen 

 measured belongs to the Essex Institute. 



S. platyrliinus differs greatly from it, being much larger and stout- 

 er ; having a disproportionately longer tail and hind feet, the latter 

 being about twice the length of the fore feet ; possessing 32 teeth, 

 with the five premolars imbricated ; and having a much broader and 

 depressed nose, which is not longer in proportion. The color, also, is 

 different, being in the latter species nearer chestnut-brown, with 

 scarcely any shade of olive-brown even on the back ; while the feet, 

 under surface of the tail, and a broad space around the mouth, 

 including the lips and chin, are nearly pure white ; the feet are nearly 

 destitute of hair in my specimens, and have no fringe along the sides. 

 The ears, also, are more distinctly rounded, whiter, and less hairy. 



* The specimen of S. Cooperi, from Danvers, Mass., of which the measure- 

 ments are given in the table, is the smallest one that I have ever seen, of this 

 species. It belongs to the collection of the Essex Institute. 



