Editorial Comment. 115 
of Mr. W J McGee, with representation of the waning ice- 
sheet and the lakes and paha-fofming streams in ice-enclosed 
basins and channels: models of the eafions and gorges of the 
Colorado, Yosemite and Niagara ; a relief map of the District 
of Columbia and contiguous country, with coloring- of the 
Columbia, Lafayette and older formations, by N. II. Darton 
and G. H. Williams; and a model of Coon butte, Arizona, by 
Mr. G. K. Gilbert. 
The last named locality is so unique, and was the scene of 
so unusual an event in Pleistocene history, that it deserves 
special description. Coon butte, as modelled from Mr. Gil- 
bert's surveys, is an annular hill enclosing a crater, situated 
about twenty-five miles east-southeast of Flagstaff, the rail- 
way metropolis of eastern Arizona. The crater is three- 
fourths of a mile in diameter and 500 to 600 feet below the 
rim, which is elevated only 150 to 200 feet above the surround- 
ing plain. The surface limestone of the region, elsewhere 
horizontal, is steeply inclined quaquaversally in the cliffs 
around the crater; and masses of the limestone and of the 
underlying sandstone are strown in very irregular profusion 
outward from the crater to the base of the butte, which has a 
diameter of about two miles. In less amount the same debris 
reaches outward on all sides over a nearly circular area to a 
distance of about four miles. No lava, bombs, lapilli, or other 
volcanic products, were seen: and the formation of this singu- 
lar crater, somewhat like the maars of the Eifel district in 
Germany, is referred by Mr. Gilbert to a steam explosion, 
probably near the middle of the Glacial period. 
The occurrence of hundreds of small fragments of meteoric 
iron, up to about a pound in weight, and of several larger 
pieces from 20 to 000 pounds, near the crater and within three 
miles eastward from Coon butte, one piece also being at a dis- 
tance of eight miles eastward, led at first to the thought that 
a meteorite of very large size, surpassing any known example, 
might have struck this spot, buried itself out of sight, and 
thrown up a crater rim. This hypothesis, upon being tested, 
was abandoned because the volume of the raised rim was 
found by careful measurements to lie very closely equal to 
that of the crater below tin- level of the plain, and for the sec 
ond reason that a magnetic survey failed to indicate the ex- 
