4 Field Museum of Natural History — Geology, Vol. V. 



direction of the section, intersect nearly at right angles. Owing to there 

 being little difference in color in the members of the trias the figures 

 are not striking, but their elements are easily distinguishable. The 

 kamacite bands are short, straight, and unequally grouped. The kama- 

 cite is granular. The taenite ribbons are narrow but border the bands 

 regularly and show no tendency to anastomose. The fields are scat- 

 tered but tend to be of relatively large size. Often, field-like spaces 

 are filled with kamacite, distinguished from similar fields of plessite by 

 a lighter color. The plessite of the fields is of uniform color and texture 

 and homogeneous. A single, small inclusion of a rectangular form, of 

 troilite constitutes the only accessory mineral observed. A qualitative 

 test of a dissolved fragment of the meteorite reacted for nickel. A 

 quantitative analysis of the meteorite has not been made as yet. 



DAVIS MOUNTAINS 



This meteorite was found in the northern end of Davis Mountains, 

 Jeff Davis County, Texas, in 1903, by George Duncan, Jr., then a lad 

 of seven years. The locality of the find, as nearly as it can be determined 

 by the writer, was Lat. 30 55 N., Long. 104 5 W. The Davis Moun- 

 tains are shown on the Valentine sheet of the topographic maps of the 

 U. S. Geological Survey. The unusual nature of the mass was recognized 

 later by Mr. George H. Duncan of Toyah, Reeves County, Texas, a 

 town about 50 miles northeast of the place of find, and in 1913 he had 

 it brought to Toyah. The mass was then exhibited for a time in Fort 

 Worth, Texas, where a small fee was charged for the privilege of examin- 

 ing it. Prof. G. M. Butler of the Colorado School of Mines was among 

 the first to recognize the meteoric nature of the mass, his investigations 

 having been made on a piece sent to him for testing. He obtained the 

 usual figures of a medium octahedrite by etching, and determined by 

 analysis the composition — Fe 92.20%, Ni 7.54%. Specific gravity 

 7.37. This information Prof. Butler kindly furnished the Museum 

 through correspondence. In September, 19 13, the entire mass, with the 

 exception of about 5 lbs. that had been removed for testing, was secured 

 by the Museum (Mus. No. Me 1946). It is an iron meteorite weighing 

 1,520 pounds (688 kgs.) and is thus of unusually large size. Like many 

 other meteorites, the shape of this meteorite is a low, irregular cone, 

 although the cone is so low that the form might perhaps better be 

 described as shield-shaped, with the boss of the shield corresponding to 

 the apex of the cone. Further, the shield has a roughly triangular 

 rather than oval outline. On two sides of the triangle (one long and 

 one short) the edge of the shield is about a foot (30 cm.) thick and is 



