CAEBONIFEEOUS PERIOD. 101 



but they probably belong to S. midattenuata McChesney, as tliey are not 

 unlike that species and occupy a similar geological position. That species 

 is a more or less common one in the Upper Coal-Measure strata of Iowa, 

 Illinois, Missoim, and Nebraska. 



Family CYATH0PHYLLIDJ5. 



Genus ZAPHKENTIS Eafinesque et Clifford. 



Zaphrentis excentrica Meek. 



Plate VI, fig. 3 a. 



Zaphrentis excentrica Meek, 1872, Geol. Surv. Montana, Idaho, Wyoming, and Utah, 495. 



Corallum large, comparatively short, broadly tm-binate, slight curved; 

 principal septa sixty or seventy, not extending to the center of the calyx, but 

 leaving a large plain surface at its bottom ; tabulae numerous, broad, thin, 

 transverse, or a little concave ; vesicular zone comparatively narrow. Height, 

 about seven centimeters; breadth at top, about six centimeters. 



Our specimens are silicified and somewhat imperfect, but they are 

 doubtless specifically identical with Z. excentrica Meek, the type-specimens 

 of which were obtained from strata of the same period at "Old Baldy", near 

 Virginia City, Montana. 



Position and locality. — Strata of the Carboniferous period; Fossil Hill, 

 White Pine County, Nevada. 



Genus LOPHOPHTLLUM Edwards et Haime, 1850. 



Lophophyllum proliferum McChesney, sp., var. sauridens. 



Plate VI, fig. 4 a, h, c, and d. 



Cyathaxonia prolifera McChesney, 1860, Descriptions of New Paleozoic Fossils, 75. 

 Cyathaxonia, sp., Geinitz, 1866, Carbonformat. und Dyasin Nebraska, 65-66. 

 Lophophyllum proU/erum Meek, 1872, U. S. Geol. Surv. Nebraska, 144. 



Corallum conical or elongate-conical, usually cui-ved, rarely almost 

 straight, tapering to a more or less slender point at its proximal end ; trans- 

 verse section circular; sm-face marked by longitudinal strise of uniform 

 size, some of which are continuous from the apex to the rim of the calyx, 

 but the additional striae required by the increasing diameter of the corallum 

 are often so arranged as to form a kind of longitudinal suture by commenc- 

 ing successively along the side of an outer stria of a series that are continu- 



