Cyclotus 19 Omphalotropis 3 Helicina 18 Georissa 3 Anodonta 1 Cyrena 3 Corbicula 7 _Islands adjacent to the Philippines._--The Philippines are connected with Borneo by two distinct ridges or banks of elevation, which enclose between them the Soo-loo or Mindoro Sea. There can be little doubt that these ridges represent the ancient highway of transit, by which Indo-Malay species passed into the Philippines. The depth of the sea on either side is profound, ranging from an average of about 1000 fathoms west of Palawan to 2550 off the south-west coast of Mindanao. It appears that the fauna of the Soo-loo ridge is definitely Philippine up to and including Bongao, Sibutu, and Bilatan, the last islands at the Bornean end of the ridge. On these are found two species of _Cochlostyla_ and an _Obbina_. The Palawan ridge may also be described as more or less Philippine throughout. One species of _Cochlostyla_ occurs on Balabac, just north of Borneo, and two on Palawan, but these are perhaps counterbalanced by the definitely Indo-Malay _Amphidromus_ and _Opisthoporus_ (1 sp. each). At the northern end of the ridge, on Busuanga and Calamian, the Philippine element predominates. Representatives of two remarkable groups of _Helix_ (_Camaena_ and _Phoenicobius_) occur along the Palawan ridge and in Mindoro. The _Phoenicobius_ find their nearest allies in the curious small group known as _Obba_, from N. Celebes, the _Camaena_ possibly in a type of _Helix_ (_Hadra_) occurring in New Guinea and N.E. Australia. The only other _Helix_ from the whole of the E. Indies which bears any resemblance to the _Phoenicobius_ group is _H. codonodes_ Pfr., which is peculiar to the Nicobars. A few forms assigned to _Camaena_ also occur in Further India and Siam. It would appear possible, therefore, that these two isolated groups are a sort of survival of a fauna which perhaps had once a much more extended range. (2) The =Chinese Sub-region=.--The _Chinese Sub-region_ includes the whole of China from its southern frontier up to and including the basin of the Blue or Yang-tse River, together with the coast district, including Corea, perhaps as far north as Vladivostok, and the outlying islands of Hainan, Formosa, the Loo-Choo and Bonin groups, and Japan to the north of Niphon. It may be divided into two provinces, the Chinese and the Japanese.