PLATE XXXVI 



PAGE 



Figs. 1-3. MACLUEITES SORDIDUS (Hall) 298 



I, 2. Lower side of two specimens. 



3. Upper side of a partial cast. 



Ordovician (Canadian), Beekmantown Is., Beekmantown, 

 New York. 



Figs. 4, 5. PLEUROTOMARIA ?? CAXADENSIS Billings 289 



4. Side view of a cast. 



5. View showing spire of specimen with shell preserved. 



Ordovician (Canadian), Beekmantown Is., Leeds and Gren- 

 ville counties, Canada. 



Figs. 6, 7. RAPHISTOMIXA LAURENTIXA (Billings) 308 



6. Side view. 



7. Top view of a cast. 



Ordovician (Canadian), Romaine formation, Mingan Islands, 

 Canada. 



Figs. 8, 9. HOBMOTOMA ARTEMESIA (Billings) 291 



8. Cast of the interior of a fragment. 



9. A partly restored, well preserved specimen. 



Ordovician (Canadian), Beekmantown Is., Leeds and Gren- 

 ville counties, Canada. 



Figs. 10-12. ISOCHILIXA GREGARIA Whitfield 363 



10. View of right valve and outline showing elevation. X 4. 



II. Left valve of a larger example, with sketch of outline. X 4. 

 12. Internal cast of right valve and outline. X 4. 



Ordovician (Canadian), Beekmantown Is., east shore of Lake 

 Champlain, Vermont. 



Fig. 13. PLIOMEROPS SALTERI (Billings) 359 



Pygidium. Enlarged. 



Ordovician (Canadian), Beekmantown Is., Phillipsburg, 

 Quebec. 



Fig. 14. GONIURUS CAUDATUS (Billings) 340 



Pygidium, illustrating the large triangular. spine. 



Ordovician (Canadian), Division G and H of the Quebec 

 group. Port aux Choix, Newfoundland. 



Fig. 15. CERATOPEA KEITHI Ulrich 299 



Side and edge views of a group of specimens. 



Ordovician (Canadian), Beekmantown, Ceratopea zone, 

 western edge of Bristol. Tennessee and Wytheville, Virginia. 

 Figs. 1-3, 10-12 are after Whitfield; 4-9, 13, and 14 are after 

 Billings. 



386 



