1915.] NATURAL SCIENCES OF PHILADELPHIA. 327 



are oviparous — a further character distinguishing them from Oreo- 

 helix, which is viviparous. It is also a more primitive feature. 



Sonorella hachitana (Dall). Plate V, figs. 4, 4a, 46. 



Epiphragmophora hachitana Dall, Proc. U. S. Na't. Mus., XVIII, p. 2, 1895; 



XIX, p. 33S, 1896. 

 Sonorella hachitana (Dall), Pilsbry, Proc. A. N. S-. Phila. for 1900, p. 556, 



1901; 1905, p. 2,57 (in part). 

 Sonorella hachitana (Dall), Bartsch, Smithsonian Misc. Coll., vol. 47, p. 



190, PI. 31, fig. 2 (shell of type); PI. 29 (apex), 1904. 



As this species is type of the genus Sonorella,^ the investigation 

 of its soft anatomy had become a matter of importance, and to 

 obtain living material was one of the chief objects of our quest in 

 the Hachetas. 



We found it at Stations 7, 8, 10 and 11. All of these stations are 

 near or on Dr. Mearns's route to the summit of Hacheta Grande. 

 Station 7, on the western slope of a hill at the head of the northern 

 branch of Western Canyon, was the most prolific locality. Here 

 the Sonorellas may be found in some numbers under large stones 

 on the steep slope near the hill-top, where there is some shade from 

 the pinon pines. 



Twenty-one adult shells from this station measure as follows: 



Diam. in mm 21.5 22 22.5 23 23.5 24 



Number of shells 2 8 2 7 1 1 



The shells vary somewhat in the degree of deflection of the last 

 whorl, but very little in other respects. The last whorl descends 

 more than in most related species. The color is pale fawn, fading 

 to whitish in the middle of the base, and having a cinnamon-brown, 

 shading into chestnut-brown, band above the periphery; this band 

 is bordered with white on both sides. The aperture is rather small, 

 its greatest diameter (including peristome) being 50 to 54 per cent. 

 of the diameter of the shell. 



At Station 8 only dead shells were found, but these are more 

 variable in size, the extremes in a lot of 8 measuring: 



Alt. 13.5, diam. 25.5 mm.; aperture diam. 13.6 mm. 

 u ^^ u 21.3 " " " 10.8 " 



5 Epiphragmophora hachitana Dall was originally designated as the type of 

 Sonorella, but the soft anatomy of the genus was described from New Mexican 

 specimens of what was subsequent^ determined as a small form of S. ashumni 

 Bartsch, a species which at that time had not been discriminated from S. hachi- 

 tana. The dissection of topotj^^es of hachitana shows that the New Mexican 

 form is specifically distinct, though closely allied. 



