Couilwuyia.~\ GASTROPODA. 193 



1. Couthouyia corrugata, Hedley, 1904. Plate 35, fig. 15. 

 Couthouyia corrugata, Hedley, Rec. A.M., v, pt. 2, 95, f. 22 in text. 



Shell very small, fusiform, thin and fragile. Sculpture : Numerous 

 growth-lines cross the whorl irregularly, and assume the aspect of 

 varices ; the whorls are crossed by faint, shallow, close, spiral grooves. 

 Colour white. Spire elevated, conical, about the same height as the 

 aperture, outlines convex. Protoconch small, of 1^- convex micro- 

 scopically obsoletely reticulated whorls. Whorls 4|, rounded, con- 

 stricted at the sutures, last whorl finally free. Suture deep. Aper- 

 ture slightly oblique, elliptical. Peristome continuous, separated from 

 the body-whorl by a deep groove, thickened and reflected. Columella 

 broad and excavate. Operculum unknown. 



Diameter, 1-55 mm. ; height, 2-58 mm. (type). 



Animal unknown. 



Type in the Australian Museum, Sydney. 



Hob. Foveaux Strait, type (A. Hamilton) ; Snares, in 50 fathoms 

 (Captain Bollons) ; near Cuvier Island, in 38 fathoms (Captain Bollons). 



Fam. PLANAXID.E, Adams. 



Animal with a rather long rostrum, subulate tentacles and eyes 

 on swellings at their base. Siphon very short ; foot simple. Central 

 tooth of radula trapezoid ; lateral tooth broad in front, with a few 

 denticles on each side of the cusp, much narrowed at the base ; mar- 

 ginals straight, long, finely pectinate. 



Shell oval-conic, spire elevated, without varices ; columella flat- 

 tened, truncate anteriorly ; lip rounded, simple, notched in front ; oper- 

 culum corneous, subspiral. 



Genus 1. PLAN AXIS, Lamarck, 1822. 

 Planaxis, Lam., A.s.V., vii, 50. Type : P. sulcatus, Born. 



Shell imperforate, oval-conic, solid, with epidermis, and elevated 

 spire, usually spirally sulcate ; columella callous, flattened, truncate 

 at base, with a narrow sinus ; interior of aperture ridged, base notched ; 

 operculum paucispiral, with a nearly terminal nucleus. 



Amphibious, crawling on stones near the margins of pools left by 

 the retiring tide, or adhering to mangrove-roots. 



About fifty species are known, tropical or subtropical. 



Fossil in the Pliocene of the West Indies. 



Sect. 1. HINEA, Gray, 1847. 



Shell smooth, covered by an epidermis ; whorls flattened ; outer 

 lip thickened, and grooved within. 



7-Moll. N.Z. 



