DESCRIPTION* OF SPECIES 165 



Iowa, and Illinois, and also from the Cuyahoga shale of Ohio, but it 

 can be distinguished from that species by its much smaller size and slender 

 form, as well as by the more regular arrangement and more uniform 

 number and size of the pores between the zooecia apertures, which 

 are generally four and occur in two rows. In S. major these pores vary 

 considerably in size and are usually four to six in number, but may 

 range from three to twelve. 



Horizon and locality. Lower Mercer limestone: Licking County, 

 Bald Knob, Locality 46, r. 



Genus Cystodictya Ulrich 

 Cystodictya carbonaria (Meek) 



1871 Ptilodictya (Stictopora) carbonaria. Meek, Proc. Nat. Sci. Phil., p. 160. 



Lower Coal Measures: Newark, Ohio. 

 1875 Ptilodictya (Stictopora} carbonaria. Meek, Pal. Ohio, Vol. II, p. 328, PI. 20, 



Figs. 3a, b. 



Coal Measures: Newark, Ohio. 

 1887 Cystodictya carbonaria. Foerste, Bull. Den. Univ., Vol. 2, p. 74, PI. 7, Figs. 2a-c. 



Coal Measures: Bald Hill, Ohio. 



Remarks. Cystodictya carbonaria is one of the most characteristic 

 and widely distributed bryozoans of the middle Pottsville formation. 

 It is most common in the Lower Mercer member, especially in Mus- 

 kingum and Licking counties along Flint Ridge; it is also present in 

 the Upper Mercer member. As far as present knowledge goes, the 

 species is confined to the Pottsville formation, as its presence in the 

 higher formations of the Pennsylvanian system of this State has not 

 been recorded. 



Horizon and locality. Lower Mercer limestone: Scioto County, 

 Locality 31, c; Muskingum County, Localities 43, 45, c; Licking County, 

 Localities 46, 47, 48, 49, c; Mahoning County, Locality 53, c. Upper 

 Mercer member, widely distributed, c. 



Genus Prismopora Hall 

 Prismopora sereata (Meek) 



PI. VI, fig. 21 



1875 Ptilodictya (Stictopora) sereata. Meek, Pal. Ohio, Vol. II, p. 327, PI. 20, Fig. 4. 



Lower Coal Measures: Flint Ridge, Ohio. 

 1887 Prismopora sereata. Foerste, Bull. Den. Univ., Vol. 2, p. 75, PI. 7, Figs. 6 a-c. 



Coal Measures: Bald Hill and Flint Ridge, Ohio. 



Description. As stated by Foerste, "the general features of the 

 species consist in regularly scalloped margins; the serrations are 



