200 PALEONTOLOGY OF OHIO. 



tinguished by the entire uniformity in the size of the corallites, and 

 their much greater obliquity as regards either the surface or the imagin- 

 ary axis of tTie stems. 



Locality and position: Abundant in the upper part of the Cincinnati group, Ohio. 



Chjetetes nodulosus, Mcholson. 



Plate 21, figs. 10, lOo. 



Corallum minute, dendroid, of small cylindrical stems, which vary 

 from two-thirds of a line to one line in diameter, and branch dichoto- 

 mously at intervals of about two lines. The corallites are prismatic, or 

 hexagonal, or sub-cylindrical, directed somewhat obliquely to the sur- 

 face, of two sizes. Larger corallites opening by oval or sub-circular 

 apertures, the long diameters of which correspond with the axis of the 

 stem, from six to eight in the space of one line, measured vertically. 

 The large sized corallites are surrounded in turn by exceedingly minute 

 circular tubuli. Surface exhibiting numerous minute elevations or 

 tubercles, which are sometimes conical, sometimes transversely elongated, 

 and are placed at distances of about half a line apart, thus communicat- 

 ing to the stems a characteristically nodulose appearance. 



This very distinct form is most closely allied to C. 'Dalei, Edw. and 

 Haime, but is readily separated by its much more slender and graceful 

 proportions, and the smaller size of the comparatively much more remote 

 tubercles. One specimen, which would appear to be referable here, ex- 

 hibits on transverse section about twelve distinct radiating septa meet- 

 ing in the center of each of the corallites. All the examples possess 

 tabulffi, and are quite like the other forms of Cfuetetes in their general 

 characters ; but if it should be shown by subsequent investigations that 

 radiating septa are present in addition, the species will have to be re- 

 moved from this conjunction and placed elsewhere. 



Locality andpodtion: Cincinnati group, Clermont county, Ohio. 



Chjstetes Jamesi, Nicholson. 



Plate 21, figs. 11, lia. 



Corallum of cylindrical or sub-cylindrical, usually hollow branches, the 

 diameter of which is from three to five lines, or of lobate or sub- palmate 

 masses, the extremities of which are rounded. Branches, in the ramose 



