﻿Dec, 1895.] 



SOREX VENTRALIS. 



75 



SOREX OBSCURUS VENTRALIS subsp.nov. 



Type from Cerro Sau Felipe, Oaxaca, Mexico (altitude, 10,000 feet). Type, No. 68342, 

 $ ad., U, S. Nat. Mus.,- Department of Agriculture collection. Collected August 

 26, 1894, by E. AV. Nelson and E. A. Goldman. Original number, 6636. 



General characters,— '^izQ ^m^ill', tail short; hiudfoot, 13 mm. Simi- 

 lar to S. ohscurus, but tail shorter and coloration darker, particularly 

 on under parts. 



Color. — Upper parts finely mixed brownish (inclining to dull chest- 

 nut) and dusky, the one or the other predominatiug according to the 

 pelage (the type specimen is in the brown pelage) ; under p)arts dull 

 chestnut, passing gradually into color of sides. Tail bicolor: dusky 

 above, soiled whitish beneath; line of demarcation usually distinct. 



Cranial and dental characters. — Skull and teeth similar to those of 

 S. obscitruSj but molariform teeth slightly larger. The first true molar 

 is essentially the same size in both, but the large premolar and second 

 molar are slightly larger in ventraUs. 



Measurements. — Type specimen : Total length, 104 mm. ; tail verte- 

 brae, 37 mm.; hind foot, 13 mm. Average of 7 specimens from type 

 locality : Total length, 105.4 mm. ; tail vertebrne, 37.3 mm. ; hind foot, 

 13 mm. 



General remarlcs. — It is interesting to find the common boreal Shrew 

 of British Columbia and the northern Eocky Mountains ranging south- 

 ward, in a very slightly modified form, all the way to the mountains of 

 extreme southern Mexico. 



The 7 specimens from the type locality (Cerro San Felipe) were col- 

 lected August 20 to September 1, and are about equally divided 

 between the two pelages. The 9 from, the mountains west of Oaxaca 

 were collected September 12 to 18^ and all are in the dark pelage. 



Sorex ohscurus ventralis differs from S. oreopolus much as it differs 

 from typical ohscurus^ in having the under parts dull chestnut instead 

 of ashy gray. The skull is broader and much shorter (particularly the 

 brain case) and the second upper molar is broader. 



Specimens examined.— Totixl number, 21, from the following localities, 

 all in the State of Oaxaca, Mexico : Cerro San Felipe (type locality), 7; 

 mountains 15 miles west of Oaxaca City, 9; mountains near Ozolotepec, 

 3; near Cajones, 2. 



Mean measuremen ts of Sorex ohscurus ventralis from different localities in Oaxaca, Mexico. 



Locality. 



Total 

 length. 



Tail. 



Hind 

 foot. 



JsTq. of 

 speci- 

 mens 

 in aver- 

 age. 



mm. 



mm. 



mm. 

 12.9 



13.7 



13.5 



Cerro San Telipe, Oaxaca, Mexico 



Mountains 15 miles west of Oaxaca City, Oaxaca 



Mountains near Cajones, Oaxaca 



Mountains near Ozolotepec, Oaxaca 



105.4 

 105.3 

 106 

 112 



37.3 

 41.2 

 41 

 40 



7 

 9 



2 



13.3 



3 



