VOL. XV 

 1803 



"'] PROCEEDINGS OF THE NATIONAL MUSEUM. 745 



Helix (Patiila) Hemphilli Newcomb. 

 =ir. (PatuJa) strtfjoiia Gould viir. 



Five examples, dead. 



Fort Huacliuca, Ariz., at an elevation of about 4,300 feet above the 

 sea; Dr. A. K. Fisher, May 14, 181)2. (Mus. No. 125,509.) 



The si)e<'iinens of the above, collected by Dr. Fisher, exceed in size 

 any of the numerous examples of the Hemphilli variety of sirigosa 

 that I have seen. In other respects, too, they are of interest, as they 

 exemplify within a small number of individuals a range of differentia- 

 tion from the subangnlate to the keeled or annulate whorls. They are 

 all more or less flattened and carinate, for extreme as the typical 

 Hemphilli is when compared with the typical strigosoj it is neverthe- 

 less connected by a chain of intermediate and gradually connecting" 

 forms. In some of Dr. Fisher's specimens, a supersutural groove fol- 

 lows the whorls, and one nearly fresh example shows two color-bands, 

 one above and one below the periphery. It is to be regretted that Dr. 

 Fisher did not obtain more, and living examples of this interesting 

 form from the Arizona r^ion. 



Bailey collected this form in August, 1800, ''amongf rocks at an alti- 

 tude varying from 8,000 to 11,000 feet," on the slopes of Needle Peak, 

 Lost Eiver Mountains, Idaho. The variety Hemphilli had previously 

 been obtained in Idaho by Hemphill, and has heretofore been reported 

 from Nevada, Utah, and Colorado. 



In the May, 1802, number of "The Nautilus," I published the fact of 

 the detection of Patnla strigosa (Mus. No. 123,570), by Mr. Marcus 

 Baker, of the U. S. Geological Survey, at Coon Mountain, Ariz,, about 

 10 miles south of Canyon Diablo. Mr. Baker's specimens were found 

 "scattered along the interior slopes of the crater;'' they are mostly 

 dead shells. The elevation, as stated, is between 5,200 and 5,700 feet 

 above tide level. The whole region is excessively arid, and the gen- 

 eral aspect of the shells collected by Mr. Baker imi)lies an environ- 

 ment of that kind. As a whole they are rather flat than elevated, and 

 more or less angulated at the perii)hery. The fresher examples are 

 slightly rufous, with two narrow revolving bands on the body whorl. 

 The character of the locality partially described by Mr. Baker will be 

 still better understood by the following abstract of a paper read be- 

 fore the National Geographic Society of AVashington, I). C, by Mr. G. 

 K. Gilbert, in March, 1892, and it will further give a pretty fair idea of 

 the general character of the environment elsewhere, where this remark- 

 able species and its varieties are the prevailing" forms. 



P'roiu Mr. Gilbert's paper, it appears that ('oou Mouutaiii is a curiously sliape<l 

 crater in a desolate region some three days journey from Flagstall'. The crater is 

 about three quarters of a mile in diameter, bowl shaped and (juite deej), and various 

 reasons have been given at times Ibr its existence. Near it have been discovered 

 so many specimens of meteoric iron, that it would seem almost necessarily more than 

 a mere coincidence. Speaking of tlie unequal distribution of land and water on the 

 surface of the eartli, Mr. Gilbert said that om^ reason given in explanation of that 



