126 LAND AND FRESH-WATEK SHELLS OF N. A. [PART IV. 



This is one of the few species of Strepomatidce which in the 

 absence of all other distinguishing characters rests its specific 

 weight on color alone. It is a very common species and 

 exceedingly uniform in all of its characters. 



The figure is from Mr. Anthony's type. 



69. P. striatum, Lea. 

 Trypanostoma striatum, Lea. Proc. Acad. Nat. Sci., p. 173, 1862. Jour. Acad. Nat. 



Sci., V, pt. ;i, p. 294, t. 3G, f. 124. Obs., ix, p. llfi. 

 Trypanostoma rostellatum, LEA, Proc. Acad. Nat. Sci., v, p. 272, 1SG2. Jour. Acad. 



Nat. Sci., V, pt. 3, p. 353, t. 39, f. 225. Obs., ix, p. 175. 



Description. — Shell striate, subulate, rather thin, horn-color; spire 



raised; sutures impressed; whorls about eight, somewhat convex, the 



last rather small; aperture small, subrhomboidal, whitish within; 



outer lip acute, very sinuous, expanded; columella somewhat 

 Fig. 237. 



thickened and very sinuous. 



Habitat. — Florence, Alabama; B. Pybas. 

 Diameter, "31 ; length, -95 inch. 



Observations, — Nearly a dozen of this species were received 

 among a number of small shells from Mr. Pybas. It is not 

 an attractive species, being dull horn-color and without bands. 

 The upper whorls are covered with revolving strijE which 

 rarely extend to the last one, except a single one on the upper part 

 of this whorl. It has much the form and size of Melania (^Trypanos- 

 toma) strigosa (nobis), but may at once be distinguished by the differ- 

 ence in the form of the aperture, the base of the columella of striatum 

 being rounded, while strigosa is nearly straight. The length of the 

 aperture is about three-tenths the length of the shell. — Lea. Fig. 238. 



The figure is from Mr. Lea's plate. I can detect no 

 specific difference between this and the following : — 



T. rostellatum. — Shell striate, attenuate, rather thin, horn- 

 color, without bands; spire raised; sutures very much im- 

 pressed; whorls eight, slightly convex; aperture small, 

 rhomboidal, whitish within; outer lip very sinuous ; columella bent in 

 and very much twisted. 



Operculum ovate, dark brown, with the polar point near the base on 

 the left. 



Habitat. — Florence, Alabama; Rev. G. White. 



Diameter, -30 ; length -83 inch. 



