KENTUCKY GEOLOGICAL SURVEY. 41 



Description of Species. 



Only a few of the commoner and more characteristic species 

 are here described. An idea of the luxuriance of the bryozoan 

 fauna of the Cincinnatian period has been given by the lists in- 

 cluded in preceding pages. A large number of new species re- 

 main to be described from the material now in hand, but their 

 determination will require extended study and the preparation 

 of numerous sections. It was intended to give illustrations to 

 elucidate the interior structure, particularly of the new species 

 described, but the necessary drawings could not be prepared for 

 lack of time. These illustrations will be given at some future 

 time. All the figures on the plates are natural size. They have 

 been produced by photographic process. For this work the 

 writer is indebted to Dr. Aug. F. Foerste. 



1. From the Lexington Group. 



PRASOPORA SIMULATRIX ULRICH. 



Plate 1, fig. I/ 



Prasopora simulatrix. Ulrich, Fourteenth Ann. Rept Geol. and Nat. Hist 

 Surv. Minnesota, p. 85, 18S6. Geol. Minnesota, vol. 3, p. 245, pi. xvi, 1-10, 

 1893. 



Zoarium discoid at first, with growth becoming hemispheric 

 or subconical ; very large specimens show lobes and other irreg- 

 ularities. Base usually concave, with a striated and concen- 

 trically wrinkled epitheca. Height of zoarium from 5 to 50 mm. 

 or more; diameter from 10 to over 100 mm. Zooecia with direct, 

 subcircular apertures, about 11 in 3 mm., and thin walls; at 

 the angles of junction are small, angular mesopores. Clusters 

 of larger zooecia have their centers about 4 mm. apart. No acan- 

 thopores. Internally the zooecia have a large number of cys- 

 tiphragms in overlapping series, and diaphragms. 



Occurrence : Very common in the Lexington group at Frank- 

 fort and numerous other localities. The discoid or hemispheric 

 form and rather large cells easily distinguish this form from 

 associated brvozoa. 



