DISCUSSION

The Early Permian genera Lytvophyllum? and Cystolonsdaleia provide the most obvious tie between the terranes of the McCloud Belt. Lytvophyllum? is now known to be present in all parts of the McCloud Belt except the Grindstone and Chilliwack terranes, and Cystolonsdaleia is now known to occur in four terranes of the McCloud Belt.

The newly recorded occurrence of the Permian genus Heterocaninia? in the Bilk Creek terrane now more tightly allies this terrane with the Eastern Klamath terrane, and the record of Petalaxis besti Wilson, 1982 in the Quesnel terrane strengthens correlation with the Stikine and Eastern Klamath terranes. Finally, the presence of Petalaxis occidentalis (Merriam 1942) in the Central Belt of the Northern Sierra Nevada adds to the previously documented occurrences of this Early Permian species in the Eastern Klamath and Grindstone terranes. Thus, the coral faunas in the various terranes of the McCloud Belt are quite similar to one another, implying, as do the fusulinids, that these terranes were closely associated during Early Permian time.

Of the genera mentioned above, Lytvophyllum?, Cystolonsdaleia, and Heterocaninia? are unknown in the Early Permian faunas of cratonal North America (Fedorowski et al., 2007). In contrast, two other Early Permian genera, Protowentzelella and Tschussovskenia, which are very abundant along much of the western and northern margins of the North American craton (Fedorowski et al., 2007), are very rare in rocks of the McCloud Belt. Thus, a comparison of the coral faunas of the McCloud Belt with those of the western and northern margins of cratonal North America suggests that these two regions were widely separated during Early Permian time.