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NORTH AMERICAN FAUNA. 



[No. 10. 



premolar more concave posteriorly. Mr. Nelson contributes the fol- 

 lowing note on the habits of this animal: 



At Jico this small, pale-colored Shrew was found only in the immediate vicinity 

 of town at an altitude of about 4,600 feet. There they were not uncommon in rather 

 dry, grassy situations under or near hedges bordering fields near the canyon just east 

 of the town. Most of the specimens secured were taken in Arvicola runways. Their 

 preference for rather high and dry situations was the converse of the habits of the 

 other two species of Shrews found here. 



A single specimen from Tuxtepec, Oaxaca (No. 65425), has the large 

 upper premolar unusually broad, and its posterior border moderately 

 excavated. It resembles a specimen from Choapam, Oaxaca (No. 

 68555), except that the latter has the premolar less broad. 



At Juquila, Oaxaca, Mr. Nelson found Blarina tropicalis living under 

 logs in damp places; at Orizaba, Vera Gruz, they were in thick grass 

 in the valley. 



I have not seen the type of B. tropicalis, but have assumed that the 

 specimens from Pluma and Juquila, Oaxaca, are sufficiently near the 

 type form to be used as a standard of comparison for specimens taken 

 at points farther north. 



Specimens examined. — Total number, 25, from the following localities 

 in southern Mexico : 



State of Oaxaca: Pluma, 2; Juquila, 7; Choapam, 1; Tuxtepec, 1. 

 State of Vera Cruz (specimens not typical) : Catemaco, 1; Orizaba Valley, 5; 

 Jico, 8. 



BLARINA SORICINA sp. nov. Sorex Blarina. 

 PI. 1, fig. 9. 



Type from Tialpam, Valley of Mexico (altitude, 7,600 feet). No. 50762, $ ad., U. S. 

 Nat. Mus., Department of Agriculture collection. Collected December 5, 1892, 

 by E. W. Nelson. Original number, 3989. 



General characters. — Similar to B. tropicalis in size and general 

 appearance, but much darker, and with narrower, Sorex-like skull. 



Color. — Upper i)arts uniform sooty black; under parts paler and 

 browner. 



Cranial and dental characters. — Skull resembling that of B. micrura 

 in size, but narrower, less angular, and more Sorex-like; brain case in 

 particular, higher, narrower, and more rounded. Third unicuspid 

 larger and with chestnut-tipped cusplet on inner side (obsolete in tropi- 

 caUs); large upper premolar broader and rather deeply excavated pos- 

 teriorly; first upper true molar excavated posteriorly; inferior molars 

 much smaller. 



Measurements (taken in flesh). — Type : Total length, 88 mm. ; tail ver- 

 tebrip, 23.5 mm.; hind foot, 12.5 mm. Average measurements of 3 

 specimens from type locality: Total length, 91 mm.; tail vertebrie, 

 26.5 mm. ; hind foot, 12.5 mm. 



General remarks. — Blarina soricina is very distinct from typical tro^n- 

 calis, but its relationship to the form of tropicalis inhabiting the tropical 



