364 Proceedings of the Ohio State .Academy of Science. 



less carinate, with distant, stout, laterally compressed spines, 

 .and with a r.ow of large apertures on either side of the carina. 

 Dissepiments nearly as large as the branches, in some cases 

 bent upward in the center, in others directed obliquely upward 

 from both sides of a branch, and in still others directed trans- 

 versely, and bear one to three apertures. Fenestrules more or 



IFiG. 4. — Septopora rectistyla. 



,a. • — Inside of a frond, natural size. 



lb. — Enlarged portion showing the apertures. (After Whitfield.) 



less variable and bordered, laterally, by apertures which, as a 

 ,rule, are three in number. The latter are less than their own 

 idiameter apart and have a prominent peristome. 



Reverse side not known. 



Horizon and locality. — ■ Maxville limestone. 

 :Shale-nodular zone : Kroft Bridge, White Cottage. 

 Undetermined zone: Harper Shaft, Olive Furnace. 



FENESTELLA SERRATULA-UIrich. 



1890. Fenestella serratula. Ulrich, Geol. Surv., 111., Vol. VIII, p. 544, 

 pi. 50, figs. 5-5c. 

 Keokuk group : Nauvoo, Illinois. 



'Warsaw beds : Monroe County and Warsaw, Illinois. 

 St. Louis limestone : Caldwell, Lyon, and Crittendon Counties, 

 Kentucky. 

 1894. Fenestella serratula. Keyes, Mo. Geol. Surv., Vol. V, p. 23. 

 Keokuk limestone : Keokuk, Iowa. 



