Raymond: Fauna of the Allegheny Series. 167 



11. Glaphurochilon simplex Raymond. Interior of the tail-valve (holotype). 

 Notice slight notch in posterior margin. For dorsal view of this specimen, see 

 Plate XXV'III. 2V2 times natural size. 



12. The same species. A median valve (paratype). 2J/2 times natural size. 

 Both of these valves are from the Vanport limestone at New Castle, Pa. 



13. An operculum w'hich is found quite frequently where Naticopsis torta is 

 common. It is similar to the operculum figured by Meek and Worthen (Paleon- 

 tology Illinois, Vol. V, pi. 28), and believed by them to belong to Naticopsis sub- 

 ovalus. Our specimens are from the Vanport limestone at New Castle, Pa. The 

 figure is about natural size. 



14. Naticopsis torta Meek. Two specimens from the Vanport at New Castle, 

 Pa. Approximately natural size. 



Plate XXV. 



1. Septopora biserialis (Swallow). The same specimen as is shown in figure 10, 

 plate XXIV. 2)^ times natural size. 



2. Lophophylliim profundum (Milne-Edwards and Haime). A specimen from 

 the Ames limestone at the Brilliant cut-off, Pittsburgh, Pa. Approximately 

 natural size. 



3. 4. Astartella vera Ilall. Four specimens from the Brush Creek limestone 

 at Donohoe, Pa. Approximately natural size. 



5. Enomphalus catilloides (Conrad). Five specimens from the Brush Creek 

 limestone at Donohoe, Pa. Approximately natural size. 



6. "Cyrtoceras" curtum Meek and Worthen. A specimen from the Brush Creek 

 limestone at Donohoe, Pa. Approximately natural size. The impressed lines 

 on the surface do not mark the position of the septa nor do they follow the outline 

 of the aperture. See the following plate for another view of this specimen. 



Plate XXVI. 



1. Pleurotomaria carbonaria Norwood and Pratten. A specimen from the 

 Brush Creek limestone at Donohoe, Pa. Approximately natural size. 



2. Worthetiia tabidata (Conrad). Two specimens from the Brush Creek lime- 

 stone at Donohoe, Pa. Approximately natural size. 



3. 4. Trepospira illinoisensis (Worthen). Three specimens from the Brush 

 Creek limestone at Donohoe, Pa. Approximately natural size. 



5. Spharodoma primogenia (Conrad). A specimen from the Brush Creek 

 limestone at Donohoe, Pa. Approximately natural size. 



6. Glaphurochiton carbonarius (Stevens). A median valve from the Pine Creek 

 limestone at Stoop's Ferry, Pa. 2}^^ times natural size. 



7. Petalodus ohio'ensis Safford. A specimen from the Brush Creek limestone 

 at Donohoe, Pa. Approximately natural size. This species is known under a 

 variety of names, Petalodus alleghaniensis and P. destructor being the ones most 

 frequently used. Safford gave tw-o figures and a brief description of specimens 

 obtained at Cambridge, Ohio, from a limestone at about the same horizon as the 

 Brush Creek, and Leidy later described P. alleghaniensis from a specimen obtained 

 from the Brush Creek in Pennsylvania. 



8. "Cyrtoceras" curtum Meek and Worthen. Interior of the specimen figured 

 jn the preceding plate. Notice the very deep hyponomic sinus. 



