DESCRIPTIONS OF TWO NEW SPECIES OF LAND-SHELLS DISCOVERED BY M. MOUHOT IN THE INTERIOR OF CAMBODIA.

Helix cambojiensis.

LAND-SHELLS.

Shell sinistral, deeply umbilicated, conoidly globose, rather inflated; upper portion of the whorls of a rich-toned transparent chestnut colour, edged at the satural margin with purple black; lower portion of the whorls white, turning to a delicate straw-colour by the overlying of a shining, transparent, horny epidermis, encircled below the periphery and around the umbilicus with two very decided, broad, rich purple black bands; whorls six, corrugately puckered throughout at the satural margin, the first four whorls very densely granosely wrinkle-striated in the direction of the lines of growth, the striæ gradually disappearing on the fifth whorl; aperture lunar-orbicular; lips simple, reflected partly round the umbilicus.

Out of two thousand species of Helix at present known, the only one of the same type as H. Mouhoti is the large H. Brookei, collected by Mr. Arthur Adams, in company with Sir Edward Belcher, on the mountains of Borneo, during the voyage of the ‘Samarang,’ and described by Mr. Arthur Adams in the ‘Zoology’ of that expedition. H. Mouhoti, of which Mr. Stevens has received a few specimens in various stages of growth, is even larger and more inflated than H. Brookei. In adult specimens the last whorl measures 6½ inches in circumference, 3 inches in diameter, and the shell is about 2 inches high. It differs from H. Brookei in being conspicuously, but not broadly, umbilicated, and in the mature lip not being in the least degree reflected at the margin. The lip itself (not the margin) is reflected at its junction with the body-whorl, partly round the umbilicus, as in the Nanina form of the genus. But the most striking feature of the species is the colouring. In H. Brookei the lower half of the whorls is of a uniform dark chestnut-colour; in H. Mouhoti it is pure white, turned to a bright straw colour by the overlying of a shining horny epidermis, encircled immediately below the periphery by a broad, rich, purple-black band, somewhat like the bands of the large Philippine Bulimus Reevei, but even broader and more defined on the white ground. The region of the umbilicus is also deeply and as definitely stained with the same purple-black colour. As in H. Brookei, all the specimens of H. Mouhoti are sinistral, or what is more commonly called reversed.

Bulimus cambojiensis.

This shell is either sinistral or dextral, cylindrically ovate, thick, stout and pupoid in the spire, bluish-white, tinged with a watery fawn-colour, and clouded throughout with oblique zigzag flames of the same colour, darker, but very undefined and washy; whorls seven, smooth, rather bulbous, faintly impressed concavely below the suture; aperture ovate, of rather moderate dimensions, overlaid in a very conspicuous manner across the body-whorl, and over a very thickly reflected lip, with a callous, opaque, milk-white deposit, which in the interior is stained with a beautifully iridescent violet-rose. This fine species, of which Mr. Stevens has received several specimens, measuring nearly 3 inches in length by 1½ inch in width, is a most characteristic example of a type of the Malayan province of the genus, represented by the old Bulimus citrinus of Brugnière; and it has been named after its well-authenticated place of habitation, because the species is, in all probability, confined to that locality. The islands adjacent to Cambodia have been pretty well ransacked; and we have nothing like it in species either from them or from the contiguous mainland of Siam on the west, or Cochin China on the east. This particular type of the genus appears, however, abundantly at the Moluccas, in B. citrinus; and at Mindanao, the southernmost of the Philippine Islands, in B. maculiferus. Like these two species, B. cambojiensis occurs with the shell convoluted either to the right or to the left. The shell is both larger and stouter than that of B. citrinus, differently painted, and especially characterized by its mouth of iridescent violet-rose, or what is now fashionably termed “Solferino” colour.

These descriptions are from the pen of Lovell Reeve, Esq., F.L.S., &c., and were communicated by him to ‘The Annals and Magazine of Natural History.’ See vol. vi. p. 203.

The annexed plate contains representations of several other new and interesting species of land shells discovered by M. Mouhot, and named by Dr. Pfeiffer, but which have yet to be described.

New Land Shells discovered by M. Mouhot.

G. B. Sowerby lith. W. West imp.

1. 2. Alycæus Mouhoti, Pf^r.

3. Helix deliciosa, Pf^r.

4. Bulisnus Römeri, Pf^r.

5. Clausilia Mouhoti, Pf^r.

6. Streplaxis pellucens, Pf^r.

7. Pupina Mouhoti, Pf^r.

8. Helix illustris, Pf^r.

9. 10. Helix Laomontana, Pf^r.

11. 12. Helix beligna, Pf^r.

13. Hybocistis Mouhoti, Pf^r.

14. Trochatella Mouhoti, Pf^r.

15. Helix horrida, Pf^r.