ggg GEOLOGY OF OHIO. 



Bryozoans and Corals of the Clinton Group of Ohio and 

 Indiana, with a List of Localities, and Occasional Notes. 



BRYOZOA. 



Ptilodidya lanceolata, Goldfuss, var. Americana var. nov. (Plate 36, Fig. 

 3 a, b). This form is very common at the Soldiers' Home Quarry ; 

 in the quarry in Glaser's woods five and a third miles from Dayton 

 on the Brandt pike. It is the form confused by Hall and Whitfield 

 with their Phaenopora expansa at the time of publication of the lat- 

 ter species. It is evidently closely related to the Gotland species 

 Ptilodidya lanceolata, from which it may differ in attaining a larger 

 size, or being at least broader, and in the fronds showing a tend- 

 ency towards undiilose folding laterally. 



Ptilodidya Whitfieldi, sp. nov. (Plate 28, Fig. 1 5; Plate 36 Fig. 4). This is a 

 form with, flat, not very broad fronds, with almost parallel edges, ex- 

 cept of course towards the base. One of the specimens in the Ohio 

 State University collection from Todd's Fork is 80 mm. long and 19 

 mm. broad. A second in Dr. Chas. Welch's collection from the 

 same source shows a tendency towards a falciform outline at its 

 basal extremity, but its upper two-thirds are quite straight. It is 

 11 mm. broad, 2 mm. thick, and 8'0 mm. long. A specimen in the 

 writer's collection from this locality is 8 mm. wide and 1 mm. 

 thick. This is another form confused by Hall with his Phcenopora 

 expansa in the 12th Annual Report of the Indiana Survey, 1883. 

 This form has never been seen by the writer from Dayton quarries. 



Clathropora frondosa, Hall (Plate 28, Fig. 3), Soldiers' Home, Fauver's 

 Quarry, Centreville, Todd's Fork, Ohio; Hanover, Indiana. In 

 the Clinton iron ore at Red Mountain near Birmingham, Alabama, 

 very typical specimens in Ohio State University collection. 



Clathropora Clintonensis, Hall and Whitfield (Plate 28, Fig. 4), Soldiers' 

 Home, Fair Haven, Fauver's. 



Pheenopora ensiformis, Hall, according to E. O. Ulrich in the Clinton of 

 Ohio. 



Phaenopora expansa, Hall and Whitfield (Plate 29, Fig. 1). This species 

 is probably identical with Phaenopora constellata, Hall. In the 

 Beavertown marl at Huffman's and Geo. Young's Quarries only 

 forms with low monticules and thin fronds have been found.. Low 

 monticules also predominate in the upper shaly courses at Huff- 

 man's. Medium sized monticules occur at Fair Haven ; and in the 

 upper, shaly courses at Centreville, Huffman's Quarry and Soldiers' 

 Home, the fronds are of medium thickness and only a small num- 

 *ber of interstitial cells are added to the normal number (two 

 between every cell) in the monticules. The most prominent mon- 

 ticules occur in the limestone specimens at Soldiers' Home, and 



