> Your beloved question man has written this before in another journal
> and never gotten much of an answer---or opinion.
>         "Y", with so many shells coming from Japan and Taiwan, do we not
hear
> of many species being found along the long coast of China?


We do. You just have to learn to read Chinese.
Malacology in China is at a fairly primitive stage, along with many of the
other life sciences. Following Grabau and King's Shells of Peitaiho (1928),
cooperation between Chinese and foreign malacologists became more or less
impossible until the 1980s, and that's not the sort of gap you fill in a
hurry. During their period of occupation, the Japanese did several faunal
surveys of Manchuria and other regions of China, including the Mollusca,
and Kuroda did lots of work on Taiwanese landsnails in the late thirties
and early forties. Some of this was in Venus, and some of it is in English.
Most of the works on Chinese mollusca with which westerners are familiar
have come through the window of Hong Kong via people like Scott, Bernard,
and Morton.
Nowadays, Chinese researchers are beginning to reach out a bit more, but it
will be some time before a body of really worthwhile work is built up.
There is a terrific language barrier to overcome, and most Chinese
institutions lost their libraries during the Cultural Revolution, so
producing works comprehensible to westerners is not as easy as it is, say,
in Japan.