206 RIEBECKIA. 



2. R. DECIPIENS (E. A. Smith). PI. 54, fig. 83 (and fig. 82). 



' ' Shell similar to that of S. sokotorana, but more attenuated 

 at the apex ; suture not channelled ; sculpture finer and not 

 cancellated." (Smith). 



Length 88, diameter 30 mm. ; apert. 27 mm. long. 



Length 78, diameter 25 mm. ; apert. 22 mm. long. 



Sokotra: Adho Dimellus, 3500-4000 ft. Underground at 

 base of high granite cliffs (H. 0. Forbes). 



Stenogyra (Riebeckia) decipiens E. A. SMITH, Journ. of 

 Malacol., vi, p. 37 (Jan. 22, 1898) ; Nat, Hist, of Sokotra 

 etc., p. 132, pi. 13, f. 14, young shell. 



"Larger than S. sokotorana. Although quite similar in 

 general appearance, as I have stated in the Journal of Mala- 

 cology (loc. cit.), this species is certainly distinct from 

 S. sokotorana. The top of the spire is more slender, the 

 suture is not deeply cni or channelled, and the sculpture is 

 much finer, consisting of fine lines of growth and excessively 

 fine spiral striae. It is possible that some of the shells fig- 

 ured by Martens (Conch. Mittheil, vol. II, pi. 29) may belong 

 to this species, figs. 7a, 7b, and 8 especially having a very 

 striking resemblance to it ' (Smith). 



PI. 54, fig. 82 is a copy of one of v. Marten's figures which 

 Mr. Smith believes to be referable to decipiens. 



3. R. GOLLONSIRENSIS (Godwin-Austen) . PL 54, figs. 80, 81. 

 ' ' Shell dextral, elongately turreted ; sculpture smooth, with 



shallow lines of growth; color dull white; spire turreted, 

 apex rounded, solid ; suture moderately impressed ; whorls 12, 

 sides very slightly convex ; aperture fusiform ; peristome thin ; 

 columellar margin solid, straight, and scarcely reflected. 

 (G.-A.). 



Length 61.8, diam. 18.2, alt. apert. 14.3, width 9.2 mm. 



Sokotra: On limestone at an altitude of over 1000 ft. on 

 the top of the ridge overlooking Gollonsir village, and on the 

 S. W. of it; at the west end of the island, not abundant 

 (Bent) ; Homhil, 1500-2500 ft,; under roots of bushes on the 

 top of Ilamaderu (Forbes). 



Slenogyra gollonsircnsis G. A., P. Z. S. 1881, p. 809, pi. 69, 



