MUSEUM OF COMPARATIVE ZOOLOGY. 175 



peculiar shade, it is very evident that the animal has drawn largely from the red 

 sandstone for the material to build its shell. 



Patula strigosa, v&T. fragilis, Hemphill, The Nautilus, Vol. IV. p. 17, June, 1890. 



The above is Hemphill's description. 



Patula strigosa, var. picta, Hemphill. 



Shell umbilicated, elevated or globosely depressed, of a dirty white color, stained 

 more or less with chestnut ; surface somewhat rough and uneven, covered with 

 moderately coarse oblique striae, and fine revolving lines ; whorls 6, convex, sub- 

 carinated, with a broad white band at the peripliery, and a dark zone of chestnut 

 on the upper side, extending from the peripheral band to the suture, fading out as 

 it traverses the whorls of the spire; beneath, on the base of the sliell, it is striped 

 with numerous bands that sometimes extend into the umbilicus, and also into the 

 aperture; spire elevated; apex obtuse; suture well impressed ; umbilicus moder- 

 ately large and deep, broader in the depressed than in tlie elevated forms ; aper- 

 ture nearly circular; lip simple, subreflected, its terminations approaching and 

 joined by a thin callus. Height J inch, greatest diameter 11 inches, lesser 1 inch. 



Rathdrum, Idaho. 



Patula strigosa, var. picta, Hemphill, The Nautilus, Vol. IV. p. 16, June, 1890. 

 The above is Hemphill's description. 



Patula strigosa, var. hybrida, Hemphill. 



Shell umbilicated, depressed, white, spire horn-color, surface of the shell cov- 

 ered with fine oblique striae, and widely separated revolving raised lines; whorls 5, 

 flattened above, rounded beneath, the last falling in front, and striped with two 

 faint chestnut bands ; suture well impressed ; umbilicus large, showing nearly all 

 the volutions ; aperture nearly circular ; peristome simple, thickened, its termina- 

 tions approaching and joined by a thin callus. Height | inch, diameter f inch, 

 lesser | inch. 



Near Logan, Utah. 



This is an interesting shell, as it is the beginning of the forms of strigosa. that 

 finally develop the revolving lines into prominent ribs, as seen on tlie surface of 

 var. Haijdeni, Gabb. 



Patula strigosa, var. hybrida, Hemphill, The Nautilus, Vol. IV. p. 17, June, 1890. 



The above is Hemphill's description. 



Mr. Cockerell (The Nautilus, 1890, p. 102) mentions by name only the fol- 

 lowing Colorado forms: — 



p. strigosa Cooperi, form trifasciata, Ckll. Mesa Co. 



P. strigosa Cooperi, form conjluens, Ckll. West Mountain Valley, Custer Co.; 

 Garfield Co. ; Mesa Co. 



