_The Cingalese district_, which almost approaches the character of a distinct province, presents several remarkable points of dissimilarity from the rest of India. It consists of the island of Ceylon, and of a portion of S. India whose exact limits have yet to be defined. It appears, however, that the Western or Malabar coast, with the hills parallel to it, is more akin to Ceylon than the Eastern or Coromandel coast. The Travancore, Malabar, and S. Canara districts, with the Palnai, Anamalai, and Nilghiri Hills, are markedly Cingalese, while there seems to be no distinct evidence of similar relationship on the part of the Madras or even the Cuddalore district. Among the principal features of the Cingalese district is the occurrence of three peculiar genera of _Helix_, one (_Acavus_) large and finely coloured, another (_Corilla_) smaller, with a singularly toothed aperture. While the _Corilla_ group shows relations with _Plectopylis_ and other Burmese and Siamese sub-genera _Acavus_ (Fig. 204) is totally distinct from any other Indian form, and shows signs of close relationship, in the great size of the embryonic shell, to the Helices of Madagascar (p. 335). In Ceylon the group is entirely isolated, and its occurrence, besides decisively separating that island from India, Burmah, and Siam, forms a most interesting problem in the history of distribution. _Eurystoma_, with a single species (_E. vittata_ Müll.), is also peculiar. As usual when _Helix_ gains ascendancy, the Naninidae retrogress. _Durgella_, _Austenia_, and _Girasia_ are absent altogether, while _Macrochlamys_, _Sitala_, _Kaliella_, etc., are present in greatly diminished numbers. The sub-genus _Beddomea_ is peculiar, a form directly related to _Amphidromus_ (Siam and Malacca). The fresh-water operculate _Philopotamis_ is peculiar, but for one species found in Sumatra; while _Tanalia_ is quite peculiar. But the forms which, next to the _Helices_, most emphasise the separation of the Cingalese district are the land operculates. There are eleven genera or sub-genera of land operculates which do not occur in the rest of India proper. Two (_Aulopoma_ and _Cataulus_) are quite peculiar, while the other nine are represented in Burmah, Siam, and the Malay islands, but not in India. On the other hand, _Diplommatina_ and _Alycaeus_, so profusely abundant in India, have not yet been discovered in Ceylon. Among the slugs, _Tennentia_ is a peculiar genus, whose nearest relation occurs in the Seychelles. [Illustration: FIG. 204.--_Helix_ (_Acavus_) _Waltoni_ Reeve, Ceylon, showing embryonic shell (_emb_). × ⅔.] _Genera and Subgenera occurring in the Cingalese District, but not in N. and Central India_ Streptaxis Tennentia Acavus Eurystoma Corilla Beddomea Philopotamis Tanalia Theobaldius Leptopomoides Craspedotropis Pterocyclus Aulopoma Ditropis Cyathopoma Mychopoma Cataulus Nicida Opisthostoma