1917.] NATURAL SCIENCES OF PHILADELPHIA. 83 



MOLLUSCA OF THE SOUTHWESTERN STATES, VIII: THE BLACK RANGE, 



NEW MEXICO. 



BY H. A. PILSBRY AND J. H. FERRISS. 



In the summer of 1915, beginning in the second week of August, 

 we collected in the Black Range of New Mexico. Approaching 

 from the west, by way of the Mimbres Valley and up Gallina Canyon, 

 we reached the crest above the head of Silver Creek. Subsequent 

 camps were made at intervals from Sawyer Peak, the southern end 

 of the range, to Reed's ranch on Black Canyon, our route being along 

 the crest trail, with numerous short trips down the slopes, and a two- 

 day trip to Kingston, in the eastern foothills. After September 12th 

 Ferriss continued the exploration alone, in Morgan and Diamond 

 Creeks on the main range, then eastward to Chloride, the Cuchillo 

 Mountains and the San Mateo Mountains, west of San Marcial, 

 in the southern edge of Socorro County. Travel was by pack train. 

 Throughout the trip we had the services of an excellent packer, 

 Teodoro Solis, a native of Chihuahua. 



The Black Range is on the boundary between Grant and Sierra 

 Counties, about 40 miles north of Deming, New Mexico. In the 

 north it forms part of the continental divide. The Mimbres River 

 Valley on the west isolates the Black fronl the Mogollon Range and 

 its outliers. The range is narrow and sharp, its flanks deeply fur- 

 rowed, but without long spurs. Hillsboro Peak is 10,000 ft. high. 

 Much of the crest trail is from 8,500 to slightly over 9,000 ft. elevation. 



Fine forest extends down nearly to the 7,000-foot contour. It 

 has been well protected against fire and its remoteness has deterred 

 the lumberman. The . yellow pine, spruce and quaking asp are 

 large and the ground well covered with forest mold. 



There seem to be limestone outcrops on all sides of Sawyer Peak. 

 The scattered exposures of these ledges were traced from the south 

 end of the range up the west side at between 7,000 and 8,000 feet, 

 as far as Iron Creek at our Station 16. Limestone was not seen on 

 that side of the range further north, on Black Canyon or Diamond 

 Creek, where it was looked for down to about 6,000 feet. On the 

 east side limestone appears in the foothills at intervals, as around 

 Kingston and Hillsboro, at Hermosa, Chloride, and some distance 

 further north. Otherwise the Black Range is of igneous or meta- 



