THE NAUTILUS. 39 



Indian Territory : Port Gibson (C. T. Simpson), in the Cherokee 

 County, northeastern part of the Territory. 



Binney reports divesta from Vernon Co., Mississippi ; but as there 

 is no county of that name in that State, a reliable locality for the 

 species east of the Mississippi river is still wanting. Probably the 

 reference is an error for the parish in Louisiana of the same name. 



In some of the lots the lip is quite narrow and recurved ;i little at 

 the edge; and there is great variation in size, the smallest specimens 

 being from Eureka Springs, Ark., and Springfield, Mo., with a 

 diameter of 15 mm.; the largest are from Eureka Springs. Ark., 

 and Grand Cane, La., and measure 19 mm. in greatest diameter. 

 Binney gives measurements of a specimen 20 mm. diameter. 



In the Indian Territory, at Limestone Gap, Choctaw Nation. 

 (C. T. Simpson), and Tushkahoma, about 40 miles farther eastward 

 in the Choctaw Nation (J. H. Ferriss, 1899), a large form occurs, 

 diameter 21 to 27 mm., with glossy, shining surface and very fine 

 striation, the last whorl proportionately wider than in the typical 

 form, lip narrow and recurved. This is apparently a well-marked 

 sub-species, and may be called P. divesta indianorum. It adds another 

 to the small group of forms such as P. jachsoni deltoidea Simp., P. 

 cragini Call, P. kiaicaensis Simp., and Vitrea Simpsoni Pils., which 

 give a certain individuality to the fauna of a small territory in this 

 region. When the areas of the southwestern snails come to be 

 mapped, as Mr. Bryant AValker has mapped the Michigan species, 

 we will find that this tract has cpnte a number of special species and 

 sub-species. 



Polygyra vultuosa mid allied species. 



In the recently published catalogue, P. vultuosa, Henriettce. Copei 

 and Cragini were united as sub-species of the first. A careful review 

 of the forms of this group, in the light of material and hints furnished 

 by A. G. Wetherby, has caused some modifications of that arrange- 

 ment, which was originally proposed by Mr. Binney. I would now 

 define the southwestern species and sub-species of Trwdopsis thus : 

 I. Basal lip with a keel on its face. 



a. Keel slight, umbilicus narrow. P. vultuosa. 



a'. Keel very strong ; aperture lunate ; umbilicus wider. 



P. vultuosa Copei. 

 a 2 . Keel strong ; aperture triangular ; spire higher. 



P. vultuosa Henriettce. 



