MUSEUM OF COMPARATIVE ZOOLOGY. 159 



Shell widely uinbilicutcMl, discoidal, flattened, angiilated, -with a peripheral 

 keel ; whorls six to six and a half, slightly tabulated near the sutures, which 

 latter are deeply impressed ; surface finely granulated, varying in different 

 specimens ; and otherwise sculptured by conspicuous subacute ribs parallel 

 with the lines of growth both above and below, which meet, and sometimes 

 cross, the peripheral keel ; these ribs are more or less irregular and uneven, 

 of varying prominence, and are also unequally spaced, being closely crowded 

 in some places and farther apart in others. Aperture obli(|uely subangulate, 

 semilunate ; peristome moderately thickened, reflected somewhat, covering the 

 open umbilicus, and made continuous by a connecting thin deposit of callus 

 oti the labium. Color, in some specimens, dingy white to white, in others a 

 dingy reddish white, ornamented with a double revolving band, — the upper 

 stripe being whitish, the lower reddish or light chestnut just above, and con- 

 tiguous to the peripheral keel ; the pinch or fold of the keel taking up what 

 in Ildix Mormonum is the third or lower stripe of white. 



Number of specimens four, two adult and two immature, but nearly full 

 grown. 



Greater diameter, ,92 to 1.01 inches; lesser diameter, .75 to .86 inch; height, 

 .3(5 to .37 inch. 



Animal not observed. 



Stanislaus County, near Turloch, California. (Stearns). 



The form to me appears a distinct species. 



Arionta Diabloensis, J- G. Cooper, (p. 3G().) 

 The species ranges one hundred miles north of Mt. Diablo. (Cooper.) 



Arionta Traski, Newcomb. (p. 3G9.) 



Dr. Cooper gives its ranges from Los Angeles fifty miles to Fort Tejon, and 

 one hundred and fifty miles to San Luis Oliispo. He says the first four whorls 

 are hirsute. 



Arionta Dupetithouarsi, Desh. (p. .370.) 

 In the grove at Cypress Point, Monterey. 



Glyptostoma Newberryanum. (p. 374.) 

 The under surface of a large specimen is figured on Plate IV. Fig. D. 



Macroceramus Kieneri, Pfeiffer. (p. ."8.j.) 



Mr. Bland (Ann. X. Y. Acad. Sci., Vol. IL p. 127) has shown the United 

 States specimens to be distinct under tlie name of jjontifiriis, Gould. 



