Description of a New Gemis and some New Species. 129 



(in fact to be almost without) intertubular cells, smooth, calice mar- 

 gifts, aud thinuer intertubular spaces. From C. Jletcheri, Edwards 

 and Haime, aud other ramose species, it is distinguished by the 

 strongl}- granulated and thick tube walls. 



Formation and localit}-: uot uncommon at Frankfort, Bergen, and 

 other localities in Kentuck\% where the lower strata of the Cincinnati 

 Group are exposed. Collectors : Rev. H. Herzer, E. O. Ulrich. 



Ch^tetes irregularis, n. sp. (Plate XII., figs. 10, 10a, 106.) 



This form grows in small, free, and exceedingly irregular masses, hav- 

 ing a diameter varying from less than three lines to fifteen lines. 

 Surface rarely nearl}^ smooth, but is generally irregularly aud strongly 

 nodulated. Apertures of tubes polygonal, nearl}' equal in size, from 

 eight to ten occupying the space of one line; walls of tubes compari- 

 tively thin. Interstitial tubuli are entirely absent. 



Longitudinal sections of this species have a peculiar and unique ap- 

 pearance. The tubes are seen to radiate from various centers, which cor- 

 respond in number to that of the prominent nodules observed on the 

 surface. Transparent sections were taken from many specimens, but no 

 tabula? were observed crossing any of the tubes. When the tubes are 

 cut transversely they are seen to be thin- walled and polj'gonal, with 

 sometimes a small or young tube interpolated. The calcite filling the 

 tubes is of darker and lighter shades, giving sections a peculiar ap- 

 pearance, and when the ends of the tubes are observed, it is divided hy 

 quite regular but faint cruciform lines, as in C. quaclratus and several 

 other forms. 



This species is allied to C. lycojjodites, but is easily distinguished 

 bj^ its peculiar growth, and in having no diaphragms crossing the 

 tubes. It is also related to C. subglobosus, but that species differs in 

 having a more regular form, larger calices, and flexuous or wrinkled 

 tube-walls. C. irregularis marks a horizon of about five hundred and 

 fifty feet above low water mark in the Ohio river at Cincinnati, and is 

 nearly always found where that elevation is exposed. 



Formation and locality: Cincinnati Group. The best localities 

 known to me for obtaining this fossil, are at Hamilton and Morrow, 

 Ohio, at which places I obtained a large number of specimens. 



Ch^tetes subglobosus, n. sp. (Plate XII., figs. 11, llr?, 116.) 



[Eiiy .—Subglobosus , somewhat globose.] 



Brj^ozoaiy free: form globular to pear-shape; diameter from three to 



