1 88 1. J TJie Paleontologist. 35 



In the writer's catalogue of Lower Silurian Fossils — Cincinnati Group, 

 published April, 1875, this species was placed as ClicBtetes ban-aiidei, 

 Nicholson. It resemlDles, somewhat. Prof. N.'s description and figure 

 of the surface markings of that species, but on further close examination 

 the two seem to differ materially. Chcetetes barrandci is from a higher 

 formation, the Devonian, Hamilton Group, Canada. 



This species has been, by some, referred to Chcetetes nigosiis, Hall, 

 from the lozver part of the Trenton Limestone, N. Y. (Pal. N. Y., vol. i., 

 p. 67, pi. 24, fig. 2), but on comparison with the type form of that species 

 I am informed that they are not identical. And in his description. Prof. 

 H. says, " the tubes radiate almost vertically from a central axis; dia- 

 phragms numerous, regular." These features are altogether different 

 from the interior structure of M. zvhitfieldi. And the professor's figure 

 of the tube walls o{ nigosiis differs materially, also, from the former. 



The surface markings of this species, at first sight, resembles, some- 

 what, some specimens of J/. [^Chcetetes) pnlehellus, Ed. & H., but on close 

 examination the difference is readily seen. In internal structure they are 

 not at all alike. 



Position and locality: Lower Silurian Formation, Cincinnati Group, 

 at Cincinnati, between about 25 and 100 feet above low water mark of 

 the Ohio river. Quite a common species at two or three localities. 



Named in honor of the distinguished paleontologist, Prof. R. P. Whit- 

 field. 



MoNTicuLiPORA [Clicstetes) MEEKi, James. 



Ch/ETETEs MEEKI, Jamcs (Paleontologist, July 2, 1878). 



The above name was proposed for this species, as here referred to, in 

 case the specimens then examined should prove different from sp. C. 

 gracilis, which they were compared to and somewhat resemble in some 

 respects. But after further comparison and examination of a large 

 number of specimens, since that publication, the conclusion is, they are 

 distinctly different. 



The cell walls of C. gracilis are very thin, and the apertures, of un- 

 worn examples, have spine-like projections on the margins; abraded 

 specimens do not show the spines. 



The margins of cell apertures of tunvoi'n specimens of C. meeki, are 

 thin and sharp, but not spinous, and the tube walls thicker than those of 

 gracilis ; the surface of C. meeki has stellate spaces, slightly or not at all 

 raised, where the calices are larger than the average, and the inter-spaces 

 thicker. Such spaces, larger calices and thicker tube walls are not seen 

 on C. gracilis. The numerous stems and branches of C. meeki are much 

 larger and stronger than gracilis, and are often hollow, sometimes 

 flattened by pressure, when not filled with clay. Hollow specimens of 

 gracilis are not found. The calices of the latter are smaller (about 12 in 

 the space of one line) than meeki, of which there are 9 or 10 in the 

 same space. Most specimens, of both species, are more or less 

 weathered or abraded when found; margins of calices rarely perfect. 



C. meeki is found abundantly in the upper beds of the Cincinnati 



