﻿I236 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I27 



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(8) Pedicle exterior, X 1, hypotype, 117686. 



Benbolt formation, Virginia Highway 71, between Mason's store and Dicken- 

 sonville, Hansonville (T.V.A. 205-SW) Quadrangle, Va. 



(9) Pedicle exterior showing elongate pedicle foramen, X 1, hypotype, 117687; 

 (10) foramen, enlarged X 4, of the preceding; (11) ornamentation of preceding 

 specimen, X 4, view taken slightly southeast of center. 



Benbolt formation, J mile south of church, Rye Cove, Clinchport (T.V.A. 

 188-NW) Quadrangle, Va. 

 (12, 13) Respectively X 1 and X 2 enlargements of the pedicle interior showing 

 the form of the muscle area and the individual scars, hypotype, 1 17688. 



Benbolt formation, road along Little Sycamore Creek, \ mile northeast of the 

 west edge of the Howard Quarter (T.V.A. 162-NW) Quadrangle, Tenn. 

 (14) Brachial interior showing septal ridges and cardinalia, X 2, hypotype, 

 117692a. (See pi. 252, B, fig. 14, for the natural size view.) 



Benbolt formation, f mile southwest of Mount Eager Church, Hogskin Valley, 

 Powder Springs (T.V.A. 154-SW) Quadrangle, Tenn. 



Plate 254 

 Rhipidomena, Strophomena 



A. Rhipidomena mesleri Cooper, new species 868 



( 1 ) Enlargement of the pedicle valve, X 4> showing ornamentation, paratype, 

 117677; (2, 3) side and pedicle views, X 1, of a complete specimen from which 

 fig. 1 was prepared. 



Lincolnshire formation (Hogskin member) Beaver Creek, Maynardville (30') 

 Quadrangle, Tenn. 



B. Rhipidomena filicostellata Cooper, new species 867 



(4) Enlargement of the brachial exterior, X 4, of the holotype; (5) brachial view 

 of a complete specimen, X 1, holotype, 117671a; (6) posterior part of a pedicle 

 interior showing the muscle scars, X 2, paratype, 117671b. 



Sevier formation, 1 mile by road northwest of Big Springs, Binfield (T.V.A. 

 139-NE) Quadrangle, Tenn. 



C. Strophomena platyumbona Cooper, new species 945 



(7) Exterior of the pedicle valve, X 1, holotype, 117743a; (10) enlargement of 

 the preceding, X 4, showing the ornamentation; (8) slab with another pedicle 

 exterior and the brachial interior showing the cardinalia, X 1, paratypes, 117743b, 

 c ; (9) pedicle interior, X h showing the form of the muscle area, paratype, 

 H7743d. 



Carters formation (Oxoplecia bed), quarry 0.3 mile north of Gate City, 

 Leeds (15') Quadrangle, Ala. 



Plate 255 



Strophomena 



A. Strophomena costellata Cooper, new species 933 



(1-3) Brachial, side, and pedicle views of a large, complete specimen, X I, holo- 

 type, 117714a; (4, 9) respectively X 1 and X 2 of the brachial side of a com- 

 plete specimen, paratype, 117714b; (5, 8) respectively Xi and X2 enlarge- 

 ments of the pedicle side of the preceding specimen; (18) enlargement of the 

 ornamentation of the preceding specimen, X 4, showing closely spaced fila ; 

 (6, 7) brachial and pedicle views of a young individual, X 1, paratype, 117714c; 

 (10, 11) respectively X 1 and X 2 enlargements of the pedicle interior showing 

 the muscle area and pseudodeltidium, paratype, H77i4d; (14, 15) interior and 

 posterior views of a fragmentary brachial valve, X 4, showing cardinalia, 



