354 LAND AND FKESUWATER 



examples of local variation and illustrate, even in a limited area, 

 what changes of elevation and geological conditions can produce, 

 Thus A. burtii, type, from the Tertiary [Sandstone of the Barowli 

 Gorge, comes nearest to what I took on Dihirhi Purbet, on the 

 same formation and on the outer base of the mountains 60 miles 

 farther east, and may be called bvrtii, var. A. dikrangensis was 

 taken on the granite of the main mountain range, some distance 

 from the plains and at some 4000-5000 feet. 



ALTCiEUs BUREOiENSis, u. sp. (Plate CXLI, figs. 6, 6 a.) 



Locality. Burroi Gorge, Dafla Hills (Type No. 2653 B.M.) 

 ( Godivin- Austen) . 



Shell globoscly conical, urabilication narrow ; sculpture next 

 sutural tube, fine close costiilation, stronger and distant on rest of 

 the whorls, not defined on the apical; colour bleached ; spire low ; 

 suture impressed, the tube short ; whorls 4, the last between 

 sutural tube and aperture crossed by two ridges, the anterior being 

 small and indistinct ; aperture quadrate, oblique : peristome double, 

 narrow, roundly angulate on outer margin, canaliculate below j 

 columellar margin nearly vertical. 



Size: maj. diam. 2'6 ; alt. axis 1'75 mm. 



A globose form with a curious angulate aperture. 



Altc^us daflaensis, G.-A. (Plate CXLV. figs. 11, 11 a, 11 b.) 



Godwin- Austen, J. A. S. B. 1876, xlv. pt. 2, pp. 176-7, pi. vii. 

 figs. 12, 12 a, 12 6 (Type No. 2497 B.M.). 

 G. Nevill, Hand-list, i. 1878, p. 291. 



Original description : — " Shell turbinate, moderately umbilicated, 

 pale whitish or dull ochreous according to the state of the epidermis, 

 finely ribbed throughout, rather more coarsely near the commence- 

 ment of the swell of the last whorl ; on this portion the ribbing is 

 very fine and close. Spire conoid, apex blunt, suture impressed, 

 the sutural tube moderate. Whorls 4, the last swollen, then con- 

 stricted, and enlarging again into a well-raised ridge, which termi- 

 nates below on margin of the peristome, it then descends and 

 expands considerably with four deep longitudinal plications. Peri- 

 stome single (no sign of the usual outer margin), continuous, with 

 five plications on the outer margiii, the lower margin recurved. 

 Aperture oblique. Operculum multispiral, horny, with a large 

 disc-like boss in the centre front side. 



" Hah. Toruputu Peak, 7000 feet. 



" The nearest to the above is A. digitalis, H. Blf., described and 

 figured in J. A. S. B. vol, xi. 1871, from Darjeeling, but the 

 dujilieate peristome in that shell is conspicuous, and forms a 

 well-defined sharp edge where the expansion and plication of the 

 inner lip commences. By the operculum alone it can be at once 

 distinguished, and it is besides a much smaller shell. 



