264 The Ohio Journal of Science [Vol. XVII, No. 7 



Plate XI. 



Fig. 1. Trochurus phlyctainodes. A, dorsal view of cranidium with sub- 

 triangular occipital segment, exposing occipital lobes near the lateral 

 extremities of this segment; B, same, tilted so as to show the anterior 

 border; C, anterior view; D, lateral view; b, anterior border; s, probably 

 spinose tip of occipital segment; e, angle of facial suture at palpebral 

 lobe; X, broken margin of fixed cheek, outline unknown. In figure 



A, the fixed cheek extends beyond the margin of the third lateral lobes; 

 in B, the third lateral lobes form the bulbous outlines at the rear, and 

 that part of the facial suture extending from the anterior border to the 

 palpebral lobe is not preserved; in D, the occipital lobe is indicated. 

 Cedarville dolomite, at eastern Mills quarry, southwest of Springfield, 

 Ohio. 



Fig. 2. Hallicystis imago. Hall. Type, numbered 2025 in the American Museum 



of Natural History in New York City. Left margin imperfect, broken 

 off. Indication of path of gut leading from anal orifice downward and 

 toward the right. Pectinirhomb on plates 14 and 1.5 visible on right 

 margin. Racine dolomite, at Racine, Wisconsin. 



Fig. 3. Callocystites jewetti-elongata. Impression of cast of exterior of part 

 of a specimen showing the pectinirhomlj on plates 14 and 15, the 

 depressed linear area left by the dropping off of one of the ambula- 

 cralia, and the distinctly pitted surface. Cedarville dolomite, at 

 eastern Mills quarry, southwest of Springfield, Ohio. 



Fig. 4. Holocystites alternatus. Hall. Type, numbered 2020, in the American 

 Museum of Natural History. Tilted so as to show the plates aroimd 

 the anal aperture; this tilting greatly shortens the length of the lower 

 plates in the figure. The path of the gut was downward and slightly 

 toward the right from the Anal orifice, A. Racine dolomite, at Racine, 

 Wisconsin. 



Fig. 5. Dalmanella springfieldensis. A series of internal casts; A, pedicel valve; 



B, anterior view; C, lateral view of another specimen, all showing the 

 prominent dental lamellae. D, brachial valve with beak of pedicel 

 valve at top; E, lateral view of the same specimen. Cedarville lime- 

 stone, at eastern Mills quarry, southeast of Springfield, Ohio. 



Fig. 6. Callocystites jewetti-elongata. A, view of cast of interior, showing 

 pectinirhomb on plates 1 and 5, of which only the half on 5 is well pre- 

 served; the location of the pectinirhomb on plates 12 and 18 is indicated 

 at the upper right-hand margin. B, same specimen, showing pectini- 

 rhomb on plates 14 and 15. Cedarville dolomite, at Cedarville, Ohio. 



Fig. 7. Dictyonella reticulata, Hall. Type, numbered 1944 in the American 

 Museum of Natural History. Brachial valve, and beak of pedicel 

 valve, enlarged 2.6 diameters. From tlie Waldron shale at Waldron, 

 Indiana. 



Fig. 8. Dictyonella corallifera. Hall. Type, numbered 1790, in the American 

 Museum of Natural History. From the Rochester shale at Lockport, 

 New York. Original or figure 5c on plate 58 of New York Paleontology, 

 vol. 2, enlarged 2.6 diameters. 



Fig. 9. Grabauphyllum johnstoni. Interior structure, near upper .surface of 

 corallum, seen from beneath. Central tabulae, smooth beneath; 

 intermediate zone of septa connected by disseppiments well shown at 

 A; exterior zone of cysts and walls separating corallites seen above and 

 toward the right of A. Niagaran dolomite, cjuarry near McCook, five 

 miles southwest of Chicago, Illinois. 



