1918.] 



NATURAL SCIENCES OF PHILADELPHIA. 



139 



ON THE GENERIC POSITION OF SONORELLA. WOLCOTTIANA BARTSCH. 



BY H. A. PILSBRY. 



Sonoj'ella wolcottiana, described from Palm Springs, a health resort 

 at the foot of the San Jacinto Mountains, not far from the Southern 

 Pacific Railroad, has been known hitherto by the original specimens 

 collected by Mrs. H. T. Wolcott in 1903 and by a small series taken 

 by Messrs. Morgan Hebard and J. A. G. Rehn in 1910. Unfortu- 

 nately, all of these were dead shells. From the close correspondence 

 of the shell to the Sonorellas of Arizona and New Mexico, the species 

 was naturally referred to that genus. The receipt of iiving speci- 

 mens taken early in March by Dr. Emmet Rixford of San Francisco, 

 enables me to transfer it to the genus Micrarionta, chiefly known by 

 coast Helices, such sis facta, gabbi, kelleti, stearnsiana, etc. It appears 

 that a group of this genus has been adapted to the arid interior, where 

 they have assumed the appearance of the desert group Sonorella. 



Fig, 1. — Genitalia of Micrariontn wolcottiana. In the right figure another view 

 of the 9 organs, d, Diverticuhim of the spermathecal duct; ds, dart sack; 

 fl, flagellum, g, mucous glands; ov, oviduct; p, penis; pr, retractor of the 

 penis; sp, duct of the spermatheca. The mucous glands are shaded to show 

 their forms more distinctly. 



The reproductive organs are illustrated for comparison with Son- 

 orella and other Micrariontas. It will be seen that on each side of the 

 11 



