﻿PART II CHAZYAN AND RELATED BRACHIOPODS — COOPER I169 



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 hypotype, 92369^ (6) brachial interior, X 2, showing median ridge, paratype, 

 G.S.C. H45d. 

 Rockland formation, Paquette Rapids, Ottawa River, Canada. 



B. Ingria cloudi Ulrich and Cooper 700 



(7-9) Brachial, pedicle, and side views of a complete specimen, X ii hypotype, 

 JI 7559c; (10, 11) brachial and pedicle views of the preceding, X 2, showing the 

 ornamentation; (12) brachial view of a small specimen, X 1, showing acute ears, 

 hypotype, H7559e; (13) exceptionally well preserved pedicle interior, X 2, show- 

 ing ridges developed anterior to the muscle area, hypotype, 117559J; (14, 15) 

 respectively X 1 and X 2 enlargements of another pedicle interior, showing the 

 muscle area but only a slight development of the anterior thickenings, hypotype, 

 H7559d; (16) brachial interior, X I, hypotype, 117559b; (17, 18) interior and 

 posterior views of the brachial valve, X 2, showing cardinal process, short 

 median ridge, chilidium, and pallial marks, hypotype, H7559g; (19) posterior 

 of the preceding, X 4, showing cardinal process and chilidium covering it; (20) 

 brachial interior, X 2 , showing pallial markings exceptionally well developed, 

 hypotype, Ii7559f- 



Pogonip group (mottled zone 700 feet below the Eureka quartzite), base of 

 first ridge east of Frenchman Flat, Las Vegas (i°) Quadrangle, Nev. 



C. Aporthophyla typa Ulrich and Cooper 698 



(21 ) Impression of the brachial valve, X 2, showing pits left by pseudopunctae, 

 syntype, 92866c; (22) plasticine replica of the brachial interior prepared from 

 the preceding impression, X 2, showing orthoid cardinalia but pseudopunctate 

 interior surface; (23) posterior of a brachial valve showing the cardinalia, X 3, 

 syntype, 92866h; (24) impression of the pedicle interior, X I, hypotype, 117566, 

 showing short, orthoid muscle scar. 



Upper Pogonip group (lower Rhysostrophia zone), about 1 mile above the 

 entrance in Ikes Canyon, Toquima Range, Roberts Mountains (i°) Quadrangle, 

 Nev. 



Plate 164 

 Aporthophyla, Toquimia 



A. Aporthophyla aurora (Billings) 698 



(1) Exterior of the pedicle valve, X I, syntype, G.S.C. 560a; (2) same enlarged 

 X 3, to show pits left by pseudopunctae; (3) impression of the brachial exterior, 

 X 1, syntype, G.S.C. 560b. 

 Table Head series, Point Rich, Newfoundland. 



B. Toquimia kirki Ulrich and Cooper 698 



(4) Pedicle view of a large specimen, X I, hypotype, 117567c; (5) pedicle view 

 of an incomplete specimen, X 1, with outline restored, hypotype, 117567J ; (6) 

 posterior of another specimen, showing the pseudodeltidium, X 3, hypotype, 

 117567I1; (7) plasticine replica of the pedicle interior, showing form of the 

 muscle area indistinctly and the subperipheral rim, X I, prepared from the fol- 

 lowing; (9) impression of the pedicle interior showing the muscle area and the 

 depression formed by the subperipheral rim, X I, hypotype, 117567a; (8) exte- 

 rior of a large pedicle valve, X i, with outline restored, plasticine replica of the 

 exterior prepared from impression, paratype, 9i595e; (10) pedicle impression, 

 X l| counterpart to preceding, showing the large subflabellate muscle area; (12) 

 enlargement of the muscle area, X 2, of the preceding; (11, 13) respectively 

 X 1 and X 2 views of a plasticine replica of the brachial interior prepared from 

 the following; (14) impression of the brachial interior prepared by dissolving 

 the shell away from the matrix to leave the impression, X 2, hypotype, H7567d. 



