180 Trans. Acad. Sci. of St. Louis. 



associated with so many species which ally that fauna with 

 the upper yellow sandstone fauna at Burlington, with none 

 at all which suggest the Chonopectus fauna, it seems more 

 probable that Phanerotinus paradoxus is from the upper 

 yellow sandstone fauna and not from the Chonopectus fauna. 



Dentalium grand aevum Win. 



PL XV. f. 29. 



The types of this species preserved in the White collection 

 are from both the Chonopectus sandstone and the upper yellow 

 sandstone, and the specimens from the two horizons seem to 

 be identical as far as external appearances go. 



IV. THE FAUNA OF BED NO. 6. 



COBLENTERATA. 



CORALS. 



"Zaphrentis sp. undet. 



Several specimens of corals which are apparently members 

 of the genus Zaphrentis, are present in the fauna of the 

 oolitic limestone at Burlington. It is possible that two 

 species may be represented, one perfectly straight and the 

 other one curved. Additional material and a study of the 

 internal structure of these corals will be necessary before they 

 can be successfully determined. 



MOL.L.USCOIDEA. 



BRACHIOPODA. 

 Leptaena rhomboidalis (Wilck.). 



PI. XVI. f. 7-8. 



This species occurs, but not abundantly, in the oolite fauna. 

 The individuals examined do not differ essentially from the 

 ordinary form of this cosmopolitan species. 



