94 



ITOETH AMERICAN FAUNA. 



[No. 38. 



B2032-103 



Fig. 26.— Fore foot of N. g. gibbsii 

 (X 1|) . Individual referred to in 

 fig. 24. 



First 



Dental characters. — First upper incisors very short, relatively broad; 

 second and tliird small (about half as large as first incisor) , somewhat 

 laterally compressed. Upper canine larger than third incisor, trian- 

 gular, compressed, two-rooted, with a small postero-basal accessory 



cusp. First upper premolar similar to canine, 

 slightly smaller; second upper premolar large, 

 triangular, with a postero-basal cusp, a pos- 

 tero-internal basal cusplike heel, and some- 

 times with an anterior cuspHke process on the 

 cingulum, which tends to disappear with age. 

 Upper molars W-shaped in transverse section, 

 with an interior basal shelf having a distinctly 

 bicuspidate edge ; first and second molars sub- 

 equal, the third much smaller, 

 lower incisor small, spatulate, directed slightly antero- 

 interiorly; second and third lower incisors and lower canine similar 

 to first incisor, smaller, successively decreasing in size posteriorly, 

 directed obliquely anteriorly, the canine with a smaller posterior 

 basal tubercle. Lower premolars triangular, 

 each with a posterior cusplike heel and an 

 indistinct posterior median sulcus, the second 

 about twice as large as first and with a small 

 antero-basal tubercle. Lower molars M- 

 shaped in transverse section, slightly com- 

 pressed laterally (less so than in Condylura) ; 

 interior shelf low and narrow, tricuspidate, 

 the median cusp not bifid; first molar with 

 minute basal tubercle between posterior and 

 median interior cusps; first and second mo- 

 lars subequal, the third smaller. Dentition: 

 total 36. 



B2033-103 



Fig. 27.— Hind foot of N. g. gibbsii 

 (X 1^). Individual referred to in 

 fig. 24. 



3 J 



C. 



1 > 



pm. 



I; 



m. -1; 



Key to Subspecies of Neiirotrichus. 



a.^ Size smaller; color paler; length of skull less than 23.2 mm,, 



Neiirotrichus gibbsii gibbsii (p. 94). 

 a. 2 Size larger; color darker; length of skull more than 23.2 mm., 



Neiirotrichus gibbsii hyacinthinus (p. 97). 



Descriptions of species and subspecies of Neiirotrichus. 



NEUROTRICHUS GIBBSII GIBBSII (Baird). 



GiBBs's Mole. 



(PI. VI, figs. 1, la, lb, 22.) 



Urotrichus gibbsii Baird, Report Pacific R. R. Survey, vol. 8, part 1, Mammals, p. 76, 

 1857. 



Urotrichus Gibsii Lord, NaturaUst in Vancouver Island and British Columbia, p. 338, 

 1866. 



