GONIOBASIS. 213 



Reeve is a more rugose variety of the same species. Tlie 

 M. Shastaensis of Reeve, sp. 318, is a good figure of G. occata, 

 Hinds. 



Melania Shastae7isis. — Shell striate, subcylindrical, rather thin, 

 dark horn-color, banded ; spire elevated, folded at the apex; sutures 

 very much impressed; whorls convex; aperture small, ovate, white 

 within ; columella smooth, incurved and recurved. 



Operculum ovate, the polar point being near the left side and below 

 the middle. 



Habitat. — Shasta and Scott Rivers, California ; Dr. Trask : and 

 Fort Umpqua, 0. T., Smithsonian Institution. 

 Diameter, -M of an inch; length, 1-05 inches. 



Observations. — Nearly thirty specimens of this species were kindly 

 sent to me by Dr. Trask. The form and size of this species is very 

 much the same as Melania (Goniobasis) Virginica, Say. It ^ig. 424. 

 diflers in the form of the aperture, in having but a single, 

 revolving, wide band, and in being more cylindrical. The 

 Shastaensis varies like the Virginica, in being very uncertain 

 as to striation. Some of the specimens are covered with 

 minute, revolving striae, while others are almost entirely des- 

 titute of them. In every specimen before me there is a 

 broad, revolving, brown band on the middle of the whorls, more or 

 less distinct, and always with more intense color on the superior 

 whorls. This band often becomes obsolete on the inferior Avhoi-ls, 

 but when that is not the case it may be seen within the aperture 

 also. A few of the specimens have the columella slightly purple. 

 Every specimen in my possession has the apex eroded, so that the 

 number of whorls cannot be with certainty stated. I should suppose 

 the number to be nine or ten. Some of them are sufficiently perfect 

 to show several upper whorls with i*egular folds. The aperture is 

 Fiff 425 probably rather more than one-fourth the length of the 

 shell. — Lea. 



Melania rudens. — Shell uaiTowly turriculated, dull olive ; 

 whorls rounded, constricted at the sutures, spirally ridged, 

 striated, the first strongly, concentrically plicated; aper- 

 ture small, rounded. 



Habitat. ? 



06serra«ions.— Strongly characterized by the constricted sutures 

 and by the rib-like plications of the earlier \\hov\s.—Iieeve. 



