DESCEIPTIONS OF NEW HELICOID SHELLS FKOM CAPE COLONY. 



Ey H. B. Preston, F.Z.S. 



Bead 8th December, 1911. 



Helicaeion Coxr, ii.sp. 



Shell small, vitreous, very thin, transparent, shining, semi- 

 orbicular, not very depressed, very pale greenish; whorls 2^, rapidly 

 increasing, the last large, inflated, smooth ; suture impressed, rather 

 naiTOwly margined below; base of shell inflated ; columella descending 



in a gentle curve ; labrum simple, acute, projecting in front, I'eceding 

 below; aperture dilated below, broadly sub-lunate. Alt. 3'o ram.: 



diam. maj. 6'5, min. Oram. Aperture 

 Ifab. — Knysna Forest, Cape Colony. 



alt. 4, diam. 3 mm. 



Helicarion Knysnaensis, n.sp. 



Shell thin, semi-transparent, shining, pale greenish yellow, 

 depressedly turbinate; whorls 3^, rapidly increasing, the last large 

 but not dilated in front, smooth ; suture impressed, narrowly margined 

 below ; base of shell rather inflated and malleatedly wrinkled ; 



columella descending in an oblifjiie curve ; labrum projecting in 

 front, receding behind ; aperture depressedly and broadly sub-lunate. 

 Alt. 9 mm.; diam. maj. 13*73, min. ir25 mm. Aperture: alt. 7'75, 

 diam. 7 mm. 



Jlab. — Knysna Forest, Cape Colony. 



The wrinkles on the base of the shell are only visible with the aid 

 of a microscope. 



