MUSEUM OF COMPARATIVE ZOOLOGY. 



219 



5 _ 5 , 4—4 



Dental Formula 

 32 



2 ' 2 — 2 



2 2—2 3—3 



Incisors. 



(1)* "Anterior upper incisor with 

 the basal lobe more conical and further 

 forward than in the other section." 



(1)* "The upper anterior incisor 

 with the basal portion of the cutting 

 edge formed by a nearly rectangular 

 lobe, (2) the entire tooth forming only 

 a single hook." 



"Lower anterior incisor (1) stout, (2) "Lower anterior incisor (3) with two 

 much curved, (3) with two or three lobed or three lobed serrations, (1) stout, (2) 

 dentations." (4) "It extends back as muck curved, (4) not reaching posteriorly 

 for as the middle of the first molar." as far as the middle of the first molar ; 

 (5) " The first and second premolars are (5) the two first lateral, tctth entirely above 

 placed above this incisor." it." 



The variation presented by different On page 9, the teeth in section A are 

 specimens renders null distinctions 1 described as "nearly uncolorcd," — 

 and 2, the lobe being sometimes much that is, brown to the base, and in section 

 produced posteriorly. B as " bicolorcd," — white at the base 



and tipped with brown. But in B. brevi- 

 cauda, the second type of coloration is 

 also quite frequent. 



Upper Premolars. 

 (1) "The first two premolars are (1) " The first premolar tooth slightly 

 nearly equal, (2) the second usually a larger than the second. (2) The third 

 little larger; (3) the next two much decidedly smaller than cither, though larger 

 smaller; (4) the fifth very small and than in the other group. (5) The small 

 usually not visible externally. (5) The cusps on the inner side of the base of the 

 first four with a basal-colored point on first three lateral teeth, either wanting or 

 the inner side." very small." 



Exceptions. — B. cinerea : " The first 

 premolar tooth is a little smaller than the 

 second." 



B. exilipes : " The first lateral tooth is 

 rather smaller than the second," &c. 



B. Berlandieri: The first lateral tooth 

 is " rather shorter than the second." See 

 also the figures, which so represent 

 them. Hence this main distinction of 

 " first premolar tooth slightly larger than 

 the second " by no means holds. 



* The numbers prefixed to the characters in the diagnoses refer to the same char- 

 acter in each section. Those that seem to be nearly or quite synonymous in the two 

 sections are italicized. 



