PACIFIC COA.ST SPECIES. 155 



I Lave had no oi)portnnity of examining areolata, tlie only otlier 

 species found within our limits. Among the species of the genus 

 foreign to the United States, plsana, ]\liill, alone has been examined, 

 the jaw being figured by Moquin-Tandon with 2-3 ribs only, and the 

 number of the teeth being given by Thomson. 



Lingual membrane as in Arionta. 



Etipnryplia Tryoni, Newcomb. 

 Shell imperforate, globose-conic, solid, with distant, deep, strong re- 

 volving lines cutting through the strife of increase, of pro. 137. 

 a bluish ash-color above, mottled with irregular ob- 

 lique patches of brown, and with a median revolving 

 tine of dark brown, below dirty white; spire conic ; 

 apex obtuse, smooth, shining, light horn-color; whorls 

 5 to 6, scarcely convex, the last globose, descending e. Tryoni. 

 towards the aperture, inflated below; aperture oblique, subcircular, 

 small, within dark above, lighter below; peristome thickened, dirty 

 white, its terminations somewhat converging, joined by a light callus, 

 right margin slightly expanded, not reflected, that of the columella 

 dilated, scarcely reflected, appressed, obtusely subdentate. Greater 

 diameter 24, lesser 20'""^ ; height, 14™"^'. 



Helix Tryoni, Newcomb, Proc. Cal. Acad. Nat. Sci., iii, 116 (1864\— W. G. Binney, 

 Am. Jonrn. Couch., i, 47, pi. vi, figs. 1-10 (1865); L. & Fr.-W. Sh., i, 178 

 (1869). 



Fohpnita Trjioni, Tryox, Am, Jonru. Couch., ii, 319 (1866). 



Eupanjpha Tryoni, W. G. Binney, Terr. Moll., v, 37;"). 



California Region, on Santa Barbara Island and San Nicolas Island, 

 California. Both recent and fossil, the latter form very large and thick. 

 Not on San Clemente. 



The species varies in the greater or lesser development of the spire 

 and in coloring. The form figured diifers from that described in having 

 the under as well as upper surface mottled, not a dead white. An albino 

 form is also found; also a fourth variety of a uniform cream-color, show- 

 ing, however, slight traces of the revolving band. 



The animal is black. It has a thick, white, parchment-like epiphragm. 



Jaw arcuate, of uniform width throughout, ends blunt; anterior sur- 

 face with stout ribs, denticulating either margin. Figures of the jaws 

 of nine mature individuals are given, showing that the number and 

 arragenment of the ribbs is not constant, a fact noticed in other 

 Species. 



Lingual membrane (Terr. Moll., Y, Plate X. Fig. B) long and nar- 



