Fig. 207.—Ariophanta Rumphii v. d. B., Java.
The Malay peninsula is practically another island of somewhat the same shape and general trend as Sumatra, and about one-half the size. Its general relations—and the remark applies to the great Sunda Islands as well—appear to be rather more with Burmah, Tenasserim, and even the Cingalese district, than with Siam. Points of connexion between Ceylon and Sumatra, and Ceylon and Borneo, have already (p. [304]) been brought out.
Map to illustrate the
GEOGRAPHICAL DISTRIBUTION
of the Land Mollusca of the
EAST INDIAN ARCHIPELAGO
The red line marks the 100 fathom line
London: Macmillan & Co.
London Stanford’s Geogl. Estabt.
It seems not impossible, from the point of view of the land Mollusca only, that the Sunda Islands may at one time have stretched much farther into the Bay of Bengal, prolonged, perhaps, into what are now the Andaman and Nicobar groups, while Ceylon and the western side of the Deccan, united into one continuous piece of land, and possibly separated from N. India by a wide stretch of sea, extended farther eastward in a long island, or series of islands.
Java, from its Mollusca, does not appear to hold the comparatively isolated position which its mammals and birds seem to indicate. Borneo, on the other hand, is more Siamese than Java or Sumatra in respect of a group whose metropolis is Siam, namely, the tubed operculates; for while that section is represented by 3 species in Sumatra and only 2 in Java, in Borneo it has as many as 19, Rhiostoma not occurring in the two former islands at all. Alycaeus, Lagochilus, Pupina, and Cyclophorus are found throughout, but Hybocystis (Malacca, 1 sp.) does not quit the mainland. Borneo is remarkably rich in land operculates, especially noticeable being the occurrence (11 sp.) of Opisthostoma (Fig. [208]), a most extraordinary form of land shell (Ceylon, Siam), of Diplommatina (17 sp.), and Raphaulus. The occurrence of a single Papuina (Moluccas eastward) is very remarkable.
