834 E. O. ULRICH CORRELATIONS OF CHESTER FORMATIONS 



The third is represented by a specimen lacking the tegmen. So far as it 

 goes, it fits Wellers T. planus, a Paint Creek species in Randolph County, 

 very well. With these also is a species of Mesoblastus that is not exactly 

 like the Upper Ohara form of M. glaber, but does agree with the Middle 

 Gasper variety of this species. The Pentremites are peculiar in that the 

 assemblage compares very badly with that of the Pentremites found in 

 the typical Paint Creek beds in Saint Clair County; but it agrees no 

 better with those found in the Renault as typically developed in the 

 Mississippi Valley or in either the lower or the upper divisions of the 

 Gasper limestone in Kentucky. They do, however, compare much better, 

 both as concerns particular species represented and absence of others, with 

 the Pentremites found in two other portions, namely, (1) those in the 

 top limestone of the Ohara in Hardin County, Illinois, and in western 

 Kentucky — that is, the Ohara zone 4 which Weller correlates unreservedly 

 with the Renault; and (2) with those of the shaly middle beds of the 

 Gasper and in the basal part of the upper Gasper limestone in Caldwell 

 and more eastern counties in Kentucky. In fact, there are at least two 

 forms of Pentremites in these Union County beds that I can not distin- 

 guish from species previously distinguished in studying the fauna of Ohara 

 zone 4. One of these I listed in my 1917 report, but without either figures 

 or description, under the name Pentremites downeyensis. The other re- 

 ceived the manuscript name Pentremites sayi. The latter reminds and 

 may well have been derived out of P. palclieUas, a widely distributed and 

 abundant Sainte Genevieve limestone fossil, but attains much greater 

 size and has a lower base. In its further development P. sayi probably 

 passed into P. liconvei'us, which is a characteristic Upper Gasper fossil. 

 But I must add the important fact that I have two specimens of P. sayi 

 from Red Bud, Illinois, where they were collected from beds thought to 

 be of Paint Creek age. The Bryozoa are represented by an association of 

 species that is distinctly indicative of the Gasper age and not of the 

 Ohara. The few specimens of Archimedes found are of the nature of 

 A. coinpactus, whereas the only species of the genus observed in the Ohara 

 is a close relative of A. meelcanus. 



Among the surprises of the fauna is the presence of a coral that seems 

 indistinguishable from the common Shetlerville species, Amplexus gen- 

 u ulatus, in every one of four collections made at places varying from 

 two to ten miles north and east of Anna. This coral seemed a striking 

 incongruity in a fauna that is certainly younger than the Shetlerville 

 zones of the Upper Ohara until I came to study a Middle Gasper faunule 

 collected by Mr. Butts at Russellville, Kentucky, in 1919, in which two 



