208 MR. H. B. PRESTON ON AGNATHOUS 



interiorly situate and a little to one side, appears a moderately 

 small denticle. 



Alt. 4 (nearly), diam. maj. 2 mm. 



Aperture: alt. -75, diam. "5 mm. 



Hah. Jombene Hills, British East Africa, at an altitude of 

 4000 feet {A. Blayney Pei^cival). 



A very remarkable species, which, apart from the decussate 

 sculpture of the apical whorls, visible only by the aid of a micro- 

 scope, is easily separable from hitherto-described species of the 

 group by the interlocking of the parietal lamella with those on 

 the projection situated just within the aperture on the outer lip. 



Var, HERCULES, var. n. 



Differing from the typical form in its much larger size, coarser 

 sculpture, and rather more obtvise apex. 



Alt. 6'25, diam. maj. 3 mm. 



Aperture: alt, 1*75, diam. 1-25 mm. 



Hab. Urguess, British East Africa, at an altitude of 6000 feet 

 {A. Blayney Percival). 



Ennea claustrum, sp. n. (PI. XXXII. figs. 14, 14 a.) 



Shell allied to E. laqueus, but larger, more cylindrical and less 

 ovate, it has half a whorl more and is more strongly, transversely 

 costulate on all but the apical whorls ; the columella descends in 

 a much stronger curve, and instead of the broad, internal, shelf- 

 like projection, which in the present species is reduced to a very 

 slight protuberance, there is, very internally situated, a strong, 

 curved lamella on the outer wall, 



Alt. 4'75, diam. maj. 2 mm. 



Aperture : alt. "75, diam. '75 mm, 



Hab. Between the Laikipia Plateau and the Eusso Kyiro River, 

 British East Africa (A. Blayney Percival). 



Ennea mma, sp. n. (PI. XXXIY. figs. 6-6 b,) 



Shell ovately cylindrical, white, somewhat shining; whorls 7, 

 the first very small, somewhat flattened, the second rather large 

 in proportion, the third, fourth, and fifth regularly increasing 

 in length and breadth, the sixth and seventh increasing in 

 length, but diminishing slightly in breadth, the apical whorls 

 smooth, polished, the remainder rather curiously, coarsely, 

 cancellately sculptured with spiral sulci, the interstices being 

 crossed by short, closely-set ridges, which develop on the latter 

 half of the last whorl and on the base of the shell into fine 

 transverse costulse ; suture impressed, narrowly margined below 

 with white; umbilical dej)ression wide and moderately deep, finely, 

 transversely costulate; columella white, porcellanous, broadly 

 and somewhat erectly, outwai-dly expanded, slightly obliquely 

 descending, diffused into a white, rather coarsely costulate, well- 

 defined, parietal callus which reaches to the upper margin of the 



