496 Mr. 11. B. Preston on new Shells 



Hah. PoznzOj Peru, 800 metres. 



Among the fifteen specimens examined there appears to be 

 a good deal of diflFerence in the diameter of the shell, and I 

 was at first inclined to think that there might be two distinct 

 species represented ; but as they all agree in every other 

 respect, I am satisfied that they all belong to the same form. 



Stenogyra colomhmna, sp. n. (Fig. 14.) 



Shell subperforate, fusiform, vitreous, pale straw-colour; 

 apex obtuse ; whorls 6^, sculptured witii very fine transverse 

 costs ; sutures impressed, subcrenulate, and discoloured with 

 a narrow band of reddish brown, wliich appears to be painted 

 on the interior of the shell ; columella descending perpendi- 

 cularly, slightly excavated and joined to the lip above by a 

 very thin calhis. 



Alt. 28-5, diam. maj. 12 mm. 



Hab. Bogota, United States of Colombia. 



Limnea Selli, sp. n. (Fig. 15.) 



Shell ovate, thin, semipellucid, light brownish horn-colour; 

 whorls 4, sculptured with very minute punctate spiral stride 

 or scratches and fine transverse lines of growth ; sutures 

 impressed; aperture ovate, rather dilated below; peristome 

 simple ; columella descending obliquely, refiexed outward, 

 thus partly concealing the narrow pertbration and spreading 

 above into a thick callus which reaches the upper margin of 

 the peristome. 



Alt. 12, diam. maj. 7 mm. 



Aperture : alt. 7, diam. o",5 mm. 



IJab. Bogota, United States of Colombia. 



Planorhis costaricensis, sp. n. (Fig. 16.) 



Shell pale brown, corneous, depressed, concave both above 

 and below; whorls 4-5, scul})tured with coarse oblique lines 

 of growth, the body-whorl inflated and extending upwards 

 and outwards towards the aperture ; aperture obliquely lunate; 

 peristome acute, bent slightly outwards, a callus uniting the 

 points of contact with the whorl. 



Alt. maj. 9*5, diam. maj. 26 mm. 



Aperture : alt. 9, diam. 6 mm. 



/^/ab. Catalina, Province of Guanacaste, Costa Rica. 



This shell is in many respects allied to P. guadeloupensis, 

 Sow., but is much more inflated than is the case with that 

 species, and there are no traces of a peripheral keel; more- 



