(Ruan and Zhou, 1987). The conodont Idiognathoides attennata zone is equal to West European R, zone. (Wang, 1987).

It is worth noting that Eupiremites hindi Weir might extend into the Upper Carboniferous Taiyuan Formation. Shansiella tongxinensis Guo may range from the Lower Member of the Tsingyuan Formation to the Upper Carboniferous Taiyuan For- mation.

I'aleobiogeography. — There has been little previous work on the paleobiogeography of Carboniferous gastropods in China, largely because few species have been described. Description of this new fauna now permits detailed paleobiogeographic com- parisons. In general, Namurian gastropod faunas from Ningxia, China are similar at the generic level to those from Europe and North America. For example, Retispira, Euphemites, Bellero- phon, Glabrocingulum, Shansiella, Murchisonia, Naticopsis, Loxonema, Strobeus, and Meekospira are common in Europe and North America (Gordon and Yochelson, 1982, 1983, 1987; Harper 1981; Hoare 1961; King 1940; Knight 1930, 1933a, 1934a, 1934b; Whitfield, 1882). Even more significantly, there are some widespread species in Retispira, Euphemites, Glabro- cingculum, ¹ti copsis, and Strobeus (Knight 1931, 193 3b; Thein and Nitecki 1974).

The identification of Chinese forms as conspecific with species originally described from Europe or America is not simply based on published references. Type or topotype specimens were ex- amined in England, Belgium, and United States. When gastro- pod faunas are compared in detail, differences are apparent. For example, Angyomphalus and Turbonitella are known in Europe only from the Lower Carboniferous of England, Belgium, and Poland. Among the 28 species from the Ningxia region, eight

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HUAZHANG — LOWER CARBONIFEROUS GASTROPODS