74 PROCEEDINGS OF THE ACADEMY OF [VOL. LXXIV 



the valley floor, where the most careful search discovered for us 

 not a trace of a snail. No doubt there are many places where a 

 repetition of this experience would be possible. In the deep 

 canyons which gash these precipitous ranges conditions are fre- 

 quently rather more favorable for land mollusks, though even 

 here one encounters them on the slopes and rarely if at all along 

 the water-courses themselves. 



Although sometimes quite abundant, at least in the form of 

 chalky-white dead shells scattered about the surface of the ground, 

 they are often so rare that living specimens become quite difficult 

 to detect. Consequently but few have found their way into the 

 hands of students. If for practical reasons the now almost legendary 

 Helix damascenus of Gould 2 be excepted, Bowers' discovery near 

 Indio of the snail described by Yates in 1890 as Helix Carpenteri, 

 var. Indioensis, but first recorded by Orcutt in 1889, was the 

 earliest to be published. Almost simultaneously Orcutt reported 

 the occurrence of a form .of Helix from Snow Creek and Palm 

 Canyons which probably represented the species which Bartsch 

 described from Palm Springs specimens in 1903 as Sonorella wal- 

 cottiana. Meanwhile, Bryant in 1900 had described two snails from 

 the "San Jacinto Mts. " under the names bowersi and harperi. 

 Although very insufficiently known, at least one of these and 

 quite possibly both belong to the same group of characteristic 

 desert snails as those already noted. In 1904, Bartsch described 

 Sonorella bailey i orcutt i from material collected by Orcutt "in 

 the Colorado Desert." All the foregoing seem to have been de- 

 scribed or recorded in each instance from dead shells only. It has 

 only been very recently that Dr. Emmet Rixford collected living 

 examples of wolcottiana at Palm Springs which Pilsbry (:18) has 

 shown to possess the anatomical characteristics of the genus 

 Micrarionta. . And this, so far as I can discover, quite completes 

 the record, although a number of allied species of Micrarionta 

 have been described from the ranges of the adjoining Mojave and 

 Arizona deserts. 



- Micrarionta (?) damascenus (Gould 1856). 

 1856. Helix damascenus Gould, Proc. Bost. Soc. Nat. Hist., v. 6, p. 11. 

 1862. Helix pandorae (pars) Gould, Otia Conch., p. 219 (mere mention). 

 1869. Helix pandorae (pars) Binney, in Binney <k Bland, Land & Fr. W. Sh. 



N. Am., 1, ]>. ISO. 

 1892. Helix pandorae var. damascenus Cooper, Zoc, v. 3, p. 18 (brief note). 



The original locality is given by Gould as "Desert region east of California," 

 collected by Dr. Frick. Unless Frick's record is very far astray, the species 

 can have little to do with Micrarionta pandorae (Forbes). 



