434 Lt.-Col. H. H. Godwin-Austen on 



whorls 44, rounded on the periphery, convex above ; aperture 

 narrowly lunate; peristome thin, columellar margin sub- 

 oblique. 



Size : major diam. 3, alt. axis 14 mm. 



This shell is not nearly so keeled as that of L. barclayi, 

 although having fewer whorls and being much smaller. 



The animal is very small, yet the specimens are so well 

 preserved, a good deal of its form could be made out. It 

 is pale throughout, the eye-tentacles being the only dark 

 parts ; these rise rather far back on the neck and are club- 

 shaped (rig. 2 a). The foot is divided and there is a mucous 

 pore with a small process above it more or less pointed 

 (fig. 2 c). The mantle-edge overlaps the edge of the peri- 

 stome (fig. 2 a). The right dorsal lobe is triangular, the left 

 longer and narrower. The animal is ovoviviparous (rig. 2 b), 

 with often four immature shells in the oviduct, the two most 

 mature showing the ribbing of the shell. I could not make 

 out the rest of the genitalia. 



The jaw (fig. 2 d) has a very small central projection. 

 The teeth of the radula (fig. 2 e) have the formula 

 30 . 4 . 1 . 4 . 30, or 34 . 1 . 34. The central tooth and the 

 four admedian teeth are on very broad quadrate plates, 

 square above, all tricuspid, the side cusps rather low down ; 

 there is a single intermediate tooth with a single cusp on the 

 outside, succeeded by an evenly bicuspid series ; at the 18th 

 tooth the laterals become tricuspid. 



In several important characters of its anatomy this species 

 is similar to Philonesia of Sykes, described by me in ' Fauna 

 Hawaiiensis,' vol. ii. 1900 (Mollusca). The teeth of the 

 radula are of the same type, with the exception that the 

 admedian teeth are tricuspid in the Mauritian species, but 

 have a single cusp on the outside in Philonesia baldwini, 

 Ancey. 



Louisia duponti, G.-A. (PI. X. figs. 3-3 c.) 

 Locality. Island of Fourneaux, S.W. of Mauritius (Dupont), 



is. v. or. 



Shell globosely turbinate, last whorl rounded below; 

 sculpture regular, distant, engraved spiral striation on lower 

 side and all the whorls crossed by fine lines of growth ; 

 colour pale chestnut ; spire conic, sides flat, apex rounded ; 

 suture impressed ; whorls 4, regularly increasing, convex ; 

 aperture semilunate, oblique; peristome very thin, colu- 

 mellar margin scarcely thickened, not reflected, oblique. 



Size : major diam. 2'5, alt. axis 1*4 mm. 



