1905.] NATURAL SCIENCES OF PHILADELPHIA. 265 



lation is finer and less distinct than in typical granulatissima, and the 

 umbilicus is slightly wider. The supraperipheral band is wide, and has 

 no paler borders. There are 4f whorls^ the last rather deeply deflexed. 

 The embryonic shell is sculptured as in *S. hachitana. 



Huachuca Mountains, in Brown's Canyon. Types No. 87,083, 

 A. N. S. P., collected by James H. Ferriss. 



The soft anatomy is unknown, but the form, while not conspicuously 

 differentiated, is yet readily distinguishable from >S. granulatissima. 

 Specimens sent to Mr. Bartsch were pronounced by him to ''stand 

 half way between S. dalli and S. granulatissima." 

 Sonorella dalli Bartsch. 



Smiths. Misc. Coll., Vol. 47, p. 193, PI. 21, fig. 1 (October 10, 1904). 



This form is somewhat larger and more depressed than S. g. latior. 

 It is described as with "numerous microscopic granulations," but in 

 one of the type lot kindly presented by Dr. Dall these are hardly appre- 

 ciable. The type measurements are alt. 12, diam. 26.5, aperture 

 10.5 X 11.8 mm.; and Mr. Bartsch has kindly supplied the diameters 

 of the rest of the series in the U. S. National Museum, as follows : Type 

 lot, Tanner's Canyon, Huachuca Mountains, 26.5, 26.1, 25.9, 24.1, 24, 

 the last two not quite mature. Huachuca Mountains, 25.3 mm. Fort 

 Huachuca, 24.6 mm. 



The smallest mature specimen of *S'. dalli slightly exceeds the largest 

 latior by 1 mm., and the smallest adult latior measures the same as the 

 largest granidatissima. S. mearnsi Bartsch, from the San Jose Moun- 

 tains, 4 miles south of the Arizona boundary, measm-es 16 mm. diam., 

 being 1.5 mm. smaller than the smallest adult granidatissima. It is 

 quite conceivable that S. dalli and S. mearnsi are merely the extremes 

 of dimensions in a continuous series of variations in size. Since «S. 

 granidatissima is the only form of the scries known anatomically, the 

 ultimate status of the others remains in abeyance. Some or all of 

 them may prove to have valid anatomical specific characters. 



