﻿PART II CHAZYAN AND RELATED BRACHIOPODS — COOPER IO53 



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 showing cardinal process; (25, 28) brachial view, X 1 and X 2, of another com- 

 plete specimen, hypotype, 116857a; (29) posterior view of a large brachial valve 

 showing cardinal process, X 4, hypotype, 116857c; (30) brachial interior, X 3. 

 showing swellings around brachial plates, hypotype, 116857b; (31) large pedicle 

 valve, X 3, showing ovarian impressions and elongate muscle scar, hypotype, 

 n6857g; (32) brachial interior, X 3, hypotype, 116857c. 

 Horizon and locality same as preceding. 



Plate 31 

 Archaeorthis, Orthidium, Pleurorthis 



A. Orthidium fimbriatum Cooper, new species 340 



(1-3) Brachial, side, and pedicle views of a large specimen, X 3, holotype, 116855a. 



Table Head series, \ mile north of Belle Burn, Newfoundland. 

 (4) Brachial exterior, X 4, showing frill, paratype, 116854a. 



Table Head series, south side of Stearing Island, Cow Head, Newfoundland. 

 (5, 6) Exterior and side views of a large pedicle valve, X 3, paratype, 116856b. 



Table Head series, Table Point Cove, Newfoundland. 



B. Archaeorthis biconvexa Cooper, new species 293 



(7, 10) Interior and exterior of the brachial valve, X 3, paratype, 116852b; (8, 9) 

 interior and exterior of the pedicle valve, X 3, holotype, 116852a. 



Limestone lens in Womble formation, 1,100 feet south and 700 feet west of the 

 NE corner sec. 3, T. 2 N., R. 19 E., Pushmatahah County, Okla. 



C. Pleurorthis costcllata Cooper, new species 330 



(11, 12) Brachial valve, X 1 and X 2, paratype, 116845c; (13, 14) pedicle valve 

 exterior, X 2 and Xi, holotype, 116845b. 



Boulder in Mystic conglomerate, Range 6, Lot 20, 2J miles north of Mystic, 

 Stanbridge Township, Quebec, Canada. 



D. Pleurorthis convexa Cooper, new species 329 



(15, 17) Pedicle exterior, X 2 and X I, holotype, 116844c; (16, 19) brachial exte- 

 rior showing deep sulcus, X 1 and X 2, paratype, n6844d; (18) exterior of a 

 large brachial valve, X 2, paratype, 116844b; (20) an imperfect pedicle exterior, 

 X 2, paratype, 116844a; (21) brachial exterior, X 2, paratype, 116844c. 

 Horizon and locality same as preceding. 



E. Pleurorthis fascicostellata Cooper, new species 331 



(22) Exterior of a small pedicle valve, X I, paratype, 116841b; (24) impression 

 of the brachial interior prepared by burning and scraping away the shell, X 2, 

 paratype, n684ig; (25) large brachial valve, X t, paratype, 116841c; (26) pedi- 

 cle impression showing dental plate slots, X 2, paratype, n684ii; (27) large 

 brachial exterior, X I, paratype, n684id. 



Horizon and locality same as preceding. 



(23) Plasticine replica of the exterior of a large pedicle valve, X h holotype, 

 1 1 7982. 



Mystic conglomerate boulder, Range 6, Lot 21, 2.6 miles north and \ mile east 

 of Mystic, Stanbridge Township, Quebec, Canada. 



F. Pleurorthis tritonia (Billings) 332 



(28, 29) Interior and exterior of an imperfect brachial valve, X 2, holotype, 

 G.S.C. 807. 

 Limestone No. 2, in Levis shale, Levis, Quebec, Canada. 



