﻿PART II CHAZYAN AND RELATED BRACHIOPODS— COOPER 1073 



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(30) Anterior view, X 3, of a large specimen showing projections on inner sur- 

 faces of interior ribs corresponding to exterior grooves between costae; these 

 function as a sort of strainer of incoming water currents, paratype, 116914. 



Wardell formation (Hesperorthis bed), north of canyon of Gap Creek, 

 li miles west of Arthur, Cumberland Gap (T.V.A. 153-SW) Quadrangle, Tenn. 



Plate 54 

 Hesperorthis 



353 



A Hesperorthis matutim Cooper, new species • • • ■■•••-■ ' * * ' "* " ' " ' ' * 



(x) Brachial exterior, X I, paratype, io 99 75a; (2) pedicle ex tenor X , holotype 

 109975b; (3) brachial interior, X 2, paratype, io 9 975e; (4) pedicle interior, 



"SffS* ZaL, northeast corner sec. 1, T. 2 S., R. 2 W, 4 ■*- east 



of Pooleville, Murray County, Okla. 



B HesPerorthis disparilis (Conrad) = H. tricenaria (Conrad) ••••••••• 7 ' • ' 35 



R ^Brachial view of the holotype, X «, A.M.N.H. 911/1; (6-10) respectively 



pedicle exterior, posterior, anterior, side, and brachial exterior, X 2, of the 



^Pro^bly Decorah formation (Guttenberg member), Mineral Point, Mineral 

 Point (30') Quadrangle, Wis. _ 



C Hesperorthis concava Cooper, new species • ■ ' " " ' ' 



(11) Brachial exterior of a complete specimen, X I, paratype, 116917; (12-15) 

 respectively brachial, side, pedicle, and posterior views, X 2, of the same 



SP ChTumont formation, loose in the bed of Black River, just below the dam at 

 the head of the island, Watertown, Watertown (15') Quadrangle, N. Y. 



347 



D. Hesperorthis colei Cooper, new species • \"'"' ■'' \" . 



(16) Brachial exterior, X I, holotype, 48796; (17-21) respectively pedicle, ante- 

 rior, posterior, brachial, and side views, X 2, of the same specimen. 

 Decorah formation (Ion member), 8 miles south of Cannon Falls, Minn. 



E Hesperorthis tenuicostata Cooper, new species '"'"'. ''" 3S7 



(22-26) Respectively brachial, anterior, side, posterior, and pedicle views, X 1, 

 of the holotype, 116924; (27-31) respectively posterior, side, anterior, brachial, 

 and pedicle views, X 2, of the same specimen. 



Lenoir formation (shaly beds with Hesperorthis near middle of Quarry), 

 quarry on the north side of U. S. Highway II, I* miles southwest of Phila- 

 delphia, Philadelphia (T.V.A. 131-NW) Quadrangle, Tenn. 

 (32-34) Respectively posterior, brachial, and side views of another complete speci- 

 men, Xi, paratype, io 9 973a; (36-40) respectively brachial, anterior, posterior, 

 pedicle, and side views, X 2, of the preceding. 



Lenoir formation, road on North Fork, 3 miles south-southeast of North Fork, 

 Christiansburg (30') Quadrangle, Va. 

 (35) Brachial interior, X 2, paratype, 109970a. 



Lenoir formation (25 feet above the Knox dolomite), Sweetwater, Sweetwater 



(T.V.A. 131-SW) Quadrangle, Tenn. 



v 360 



F. Hesperorthis sp. 1 



(41) Brachial exterior, X 2, figured specimen, 109972. 



Botetourt formation, junction of Virginia Highways 311 and 114, i mile south- 

 west of Catawba, Salem (15') Quadrangle, Va. 



