40 



Cincinnati Society of Natural History. 



The cell-mouths are elongate-oval, and placed on the upper face of the 

 cell or subpyriform expansion. 



In our specimens, the branches frequently cross each other and give 

 the whole the appearance of forming distant and Irregular reticulating 

 meshes, but no case of anastomosing branches has been observed, hence 

 no network is in fact formed. 



The species is distinguished b}' the long delicate branches, slightly 

 expanding cells, and method of bifurcation. In some instances two or 

 three cells follow each other without a division, and in no instance 

 have I observed more than two branches arising from the same cell. 



The specific name is in honor of Dr. H. A. Prout, who did so much 

 to make known the Bryozoa from the palaeozoic rocks. The specimen 

 illustrated is from my own collection, and was found adhering to the 

 base of Anomalocrinns incurvus. 



Orthis scovillei, n. sp. 



Plate 1, fig. 5, dorsal view of a specimen, natural size: fig. 5«-, dorsal view of a smaller 

 specimen: fig. 56, interior of the dorsal valve: fig. oc.. interior of a ventral valve. 



Sheii sub-circular in outline, somewhat wider than long, cardinal 

 margin shorter than the breadth of the valves, and rounding at the 

 extremities into the lateral margins. 



Dorsal valve moderately convex, sinus not denned, beak low, area 

 narrow, surface ornamented with very coarse radiating striae, which 

 become bifid near the margin, but do not increase by intercalation. 

 About thirty' two cover the dorsal valve. Interior showing the radiating 

 striae toward the margin; scars of the adductor muscles situated on 

 each side of a strong mesial ridge, which is higher between the poste- 

 rior than the anterior pair, the former are roughly striated, and extend 

 back as far as the points of the brachial processes ; a well-defined, 

 transverse ridge separates the anterior from the posterior pair ; sockets 

 deep; brachial processes strong, and directed lateral!} 7 " forward. 



Ventral valve nearly flat, beak low, area a little wider than that of 

 the other valve, and tapering toward the extremities; surface marked 

 by veiy strong radiating striae. Interior showing the hinge teeth well 

 developed, prominent, sharp, and transversely trigonal; from the lower 

 and interior sides of these teeth ridges extend forward and curve to- 

 gether, so as to form an elevated margin, to a large and deep oval 

 cavity, extending nearly to the middle of the shell, for the reception of 

 the muscular attachments; a mesial furrow divides this cavity into 

 two equal parts, and makes a notch in the rim at the middle of the front. 



