300 



PROCEEDINGS OF THE ACADEMY OF [NoV.-DeC.^ 



embryonic shell about 1^ whorls, the first half whorl having some 

 radial wrinkles, the rest of the embryonic portion closely irregularly 

 granulose, and having fine, rather indistinct, tangential (protractive) 

 threads, often visible only near the suture. Subsequent whorls 

 have the usual fine growth-lines. The whorls increase slowly at 

 first, the last one very wide, suture descending slightly in front. 

 The aperture is rounded oval-lunate. Peristome is well expanded. 



Alt. 15.5, diam. 27 mm.; aperture 

 alt. 14.3, width 15.8 mm.; 4f whorls. 

 Tortillita Mountains, Pinal Co., 

 Arizona, the type, No. 118,053, from 

 Station 41 (1917), east side of Hog 

 Canyon; also found at Station 40, 

 west side of same canyon near the 

 cement dam, and Station 42, south 

 slope of m'ountains east of Hog 

 Canyon. 



Genitalia (Fig. 8). The penis is 

 very long and rather slender, with 

 muscular walls, containing a long, 

 slender, corrugated, tapering papilla. 

 The epiphallus is shorter than the 

 penis, without a distinct flagellum, 

 though there seems to be a rudi- 

 mentary one concealed in the integu- 

 ment. The penial retractor is long. 

 Length of vagina is about equal to 

 the penis. 



By the long penis and vagina 

 this species is related to S. rincon- 



Fig. 8. Genitalia of SonoreUa tor- ^nsis, but in that snail these organs 

 tillita with detail of the penis- are far longer. S. santaritana is even 



more like S. tortillita in genitalia, 



but the shell is flatter, the whorls of smaller caliber. None of the 



Santa Catalina species has the vagina and penis nearly so long as in 



S. tortillita. The larger shells referred to B. sahinoensis occidentalis 



are closely similar. 



The embryonic sculpture described is in large part effaced in 



the fully adult shells found. The color, too, is somewhat faded. 



In the young and barely full-grown examples it is decidedly darker 



than descri])ed. 



