128 Cincinnati Society of Natural History. 



by having the spaces between the rays of the stellate maculas raised, 

 and the tubes smaller. Interiorly we find that the tubes in the mid- 

 dle of the branch or frond are crossed by remote tabulae, and as they 

 approach the surface the curve is more abrupt than is the case in S. 

 limitaris. 



Formation and locality: the type specimens were found by the 

 author, in the upper part of the Cincinnati Group, at Clarksville, O. 



Ch^etetes GRA.NULIFERUS, u. sp. (Plate XII,, figs. 9, 9a, 96). 



\Yiiy. —Granula, a grain ; /ero, to bear.] 



Bryozoary composed of sub-cylindrical stems, which divide dichoto- 

 mously at varying distances, are sometimes irregularly thickened and 

 nodulated, and have a diameter of from two to five lines. Surface 

 generally smooth, but sometimes exhibiting obscure tubercles with a 

 distance of one and a half lines between them ; at other times again 

 the maculae, instead of being raised into tubercles, are depressed 

 below the general surface, and composed of groups of minute tubuli. 

 Tube apertures, varying from circular or oval to sub-polj-gonal, of un- 

 equal size, usually with groups of slightly larger-sized tubes, which 

 occupy the monticules when any are developed ; intercellular spaces 

 extremely thick, when well preserved are strongly granulated, some- 

 times to such an extent as to obscure the calices; when slightly worn 

 the granules or spines are seen to be simply surface extensions of 

 curiously modified minute tubuli ; this fact is demonstrated even 

 more clearly in sections taken from near the surface and parallel Avith 

 the same ; the number of these interstitial tubuli, and consequently 

 of the spinulae varies (-onsiderably in different specimens. 



In longitudinal sections the tubes are seen to be quite vertical in 

 the center of the branch, and to bend outwards to the surface in a 

 regular curve, forming an angle of about fifty degrees with the plane 

 of the surface. The diaphragms are very numerous in the tubes near 

 the surface, becoming gradually less so toward the middle or vertical 

 portion of the tubes ; here the}' are about two tube diameters distant 

 from each other. In transverse sections the tubes are ratlier thin- 

 walled, polygonal, and divided by faint, cruciform lines, similar to 

 those noticed in sections of this kind, of other species of Choiteles. 



Well preserved examples of this species can not be confounded with 

 any other species found in the Cincinnati Group. Worn specimens, 

 however, are not so easil}^ distinguished from C briareus, Nicholson. 

 By a close examination we find the latter to have much less numerous 



