Mr. W. H. Benson on the genus Alycseus, Gray. 179 



nent features, although perfectly distinct from any of its allies, 

 especially in its aperture (sinuous, and at its upper angle emar- 

 ginate), its wider umbilicus, plainer sculpture, and more com- 

 pressed whorls. 



3. Alycceus Physis, n. s. 



Testa mediocriter umbilicata, conoideo-depressa, tenui, regulariter 

 planato-striata, striis opacis, minim e elevatis, confertissimis, ad 

 umbilicum perspectivum nonnullis elevatis acutis, hyalina, nitida ; 

 spira brevi, apice subpapillari, sutura impressa ; anfractibus 4 sub- 

 convexis, ultimo ad latus, pone constrictionem, valde inflate, tubu- 

 lum suturalem elongatum gerente, pone labrum tumidiusculo ; 

 apertura obliqua, subcirculari, peristomal e duplici, interno breviter 

 expanse, incrassato-reflexo externum celante, marginibus callo 

 parietali expansiusculo semicirculari junctis. Operc. ? 



Diam. major. 10, minor 8, axis 6 mill. 



Habitat in valle Rungit (alt. 2000 ped.), prope Darjiling, raro 

 occurrens. 



Larger than the Khasia A. prosectus, from which it is abun- 

 dantly distinguished by the characters of the aperture, the less 

 mucronate spire, its peculiar striation and lustre, shorter sutural 

 tube, and the greater inflation of the last whorl. In prosectus 

 the space between the constriction and the aperture is suddenly 

 tumid near the constriction, the swelling decreasing towards the 

 peristome ; in Physis the swelling increases gradually towards 

 the mouth, which is not inclined to be so very oblique. There 

 are faint indications of spiral sculpture evident in the facet-like 

 appearance of the surface. Within the umbilicus, near the in- 

 flated part, every fourth or fifth of the scarcely elevated strise 

 (which would elsewhere be hardly distinguishable except for 

 their white opacity on the hyaline ground) is raised into a knife- 

 like edge. 



In size and form A. Physis nearly approaches umbonalis; but 

 the colour, opakeness, great solidity, and the more moderate 

 inflation of the last whorl, in addition to the more remote con- 

 striction, and the very diff'erent sculpture presented by the 

 Burmese species, preclude any danger of confounding it with its 

 Himalayan ally. 



4. Alycaus Gemmula, n. s. 



Testa umbilicata, conoideo-depressa, laevigata, nitida, ad ventriculum 

 minutissime, ad umbilicum crasse striata, hyalina ; spira conoidea, 

 apice obtusiusculo, sutura profunda ; anfractibus 4 convexiusculis, 

 ultimo compresse rotundato, turn tumido, tubulum mediocrem 

 gerente, tunc fossiculato-constricto, strictura crista recumbente, 

 demumque area planata ab apertura separata ; apertura obliqua, 

 superne arcuatim prominente, peristomate duplici, valde incrassato- 



12* 



