146 MINUTE SNAILS. 



Microphysa Lansingi^ Bland, Mi-cro-fy''-sa Lan'- 

 sing-i, has a minute, flattened shell, consisting of 

 five or six horn-colored, shining whorls, without an 

 umbilicus. The aperture is long and narrow, the 

 outer lip sharp and thin, and the diameter of the 

 whole shell is less than one-eighth of an inch. It is 

 found among damp leaves in the vicinity of Portland, 

 Oregon. 



Mycrophysa Ingcrsolli^ Bland. The shell of this 

 species is white, very thin, and almost transparent. 

 The umbilicus is distinct, the spire greatly flattened, 

 the whorls five and a half in number, the aperture 

 crescent-shaped, and the outer lip thin. The greatest 

 diameter of the shell is a quarter of an inch. It is 

 found in eastern Oregon and in Colorado. 



Vallonia pitlchella^ Miill., Val-lo'-ni-a pul-keV-la. 

 This is another little mollusk, whose shell consists of 

 four rounded whorls, arranged in a flattened spiral 

 form. The umbilicus is large and open, the aper- 

 ture nearly circular, the peristome white, reflected, 

 and forming a nearly complete circle. The shell is 

 white, thin, and in our variety it is usually marked 

 by cross ribs. Its diameter is barely an eighth of an 

 inch. The species is very widely distributed, being 

 found in northern countries all round the world. 

 The specimen described was found in Logan canon, 

 Utah. It is found also in Nevada, Idaho and Ari- 

 zona. 



Helix {Patula) striatella^ Anthony, Pat'-u-la stri-a- 

 tel'-la. The specimens of this shell were collected 

 near the same locality as those of the last, and its 

 American range is also similar. It resembles the 

 last in general shape, having four whorls, a large 

 umbilicus, a circular aperture, and low cross ribs ; 



