=_Sorex cinereus cinereus_= Kerr.--Two male (59642-59643) Masked Shrews weighing 4.8 and 4.9 grams were trapped on June 17 at locality 10, and a nonpregnant female (59644) was trapped on June 26 at locality 6. _Sorex cinereus_ seemed to be less abundant on the Mesa than _Sorex vagrans_; more individuals of _S. vagrans_ than of _S. cinereus_ were trapped on June 17 at locality 10 and on June 26 at locality 6, and _S. vagrans_ was trapped at three localities where no _S. cinereus_ was obtained. [Illustration: FIG. 1. Map of the Grand Mesa (for purposes of this paper the area above 7500 feet on each side of the northern boundary of Delta County). The inset of the western three-fourths of Colorado shows the Grand Mesa in relation to the larger areas of mountains in the state (areas above 9000 feet are stippled). The following collecting localities are indicated by numbered, black dots: (1) 2 mi. N, 9 mi. E Collbran, 7000 ft., Mesa County. (2) Land's End Road to Grand Mesa, 6800 to 8050 ft., Mesa County. (3) 3 mi. E, 4 mi. S Collbran, 6800 ft., Mesa County. (4) 3 mi. E, 9 mi. S Collbran, 10,200 ft., Mesa County. (5) 5-1/2 mi. E, 11-1/2 mi. S Collbran, _in_ Delta County. (6) 5-1/2 mi. E, 12 mi. S Collbran, 9600 to 10,400 ft., _in_ Delta County. (7) 28 mi. E Grand Junction (Sec. 29, T. 11S, R. 95W), Mesa County. (8) 6 mi. E Skyway, 10,000 to 10,500 ft., _in_ Delta County. (9) 7 mi. E Skyway, _in_ Delta County. (10) 8 mi. E, 1/2 mi. S Skyway, 9500 to 10,200 ft., _in_ Delta County. (11) 8 mi. E, 3/4 mi. S Skyway, 10,200 ft., _in_ Delta County. (12) 8 mi. E, 1 mi. S Skyway, 10,000 to 10,200 ft., _in_ Delta County. (13) 8 mi. E, 1-1/2 mi. S Skyway, 8500 to 9600 ft., _in_ Delta County. (14) 8 mi. E, 2 mi. S Skyway, 9000 ft., _in_ Delta County. (15) 8 mi. E, 2-1/2 mi. S Skyway, 9600 ft., _in_ Delta County. (16) 1 mi. S, 4 mi. W Skyway, 10,200 ft., Mesa County.] =_Sorex vagrans obscurus_= Merriam.--Fifteen specimens of the Vagrant Shrew (59645-59655, 59665-59668) were trapped in Delta County from localities 6, 10, 12, 13, and 14. The fourteen specimens having skulls fell into two distinct age-classes based on wear of the teeth as described by Findley (1955, Univ. Kansas Publ., Mus. Nat. Hist., 9:8); 5 were in the younger group and 9 in the older group. Weights in grams of the younger shrews were 4.6, 5.5, 5.7, 5.8, and 6.4; weights of the older shrews were 6.4, 6.8, 7.3, 7.4, 7.5, 8.0, 8.3, and 8.8. One of the seven females was lactating; none contained embryos. =_Sorex palustris navigator_= (Baird).--Six Water Shrews (59633-59638) were trapped in Delta County at localities 10, 13, 14, and 15. The one specimen from locality 10 was trapped on June 17; all others were taken on June 21. None was pregnant or lactating. Two are young, weighing 11.0 and 12.9 grams; the other four are older, weighing 16.6, 17.0, 19.2, and 21.5 grams.