NO. 4 CRETACEOUS BRACHIOPODA, ARIZONA — COOPER I5 



Ransome, F. L. 



1904. Bisbee Folio, Arizona. U. S. Geol. Surv. Atlas, No. 112. 

 Sahni, M. R. 



1929. A monograph of the Terebratulidae of the British Chalk. Palaeonto- 

 graphical Soc. (1927). 

 Stoyanow, a. 



1949. Lower Cretaceous stratigraphy in southeastern Arizona. Geol. Soc. 

 Amer. Mem. 38. 

 Thomson, J. A. 



1927. Brachiopod morphology and genera (Tertiary and Recent). New 

 Zealand Board of Sci. and Art, Manual 7. 



EXPLANATION OF PLATES 



Plate i 



Page 



A. Cyclothyris americana Cooper, new species 3 



1-5, Anterior, posterior, brachial, side, and pedicle views, respec- 

 tively, X I, of holotype U.S.N.M. No. 124193a. 6, Brachial 

 view of the holotype, X 2, showing elevated rim on deltidial 

 plates around the foramen. 7, Beak of young pedicle valve, 

 X 2, showing teeth and rim around foramen, paratype 

 U.S.N.M. 124186c. 8, 9, Interior of pedicle valve X 2, and 

 same tilted, showing muscle scars, thickened deltidium (del- 

 tidial plates fused), and pallial marks, paratype U.S.N.M. 

 No. I24i86d. 10, 17, Cardinalia seen from the anterior and 

 tilted, X 3. to show articulation, and anterior surface of the 

 radulifer crura, paratype U.S.N.M. No. 124186a. 11, 12, Pos- 

 terior of a young specimen, X 4. showing elevated rims on 

 foramen before formation of the deltidium, paratype U.S.N.M. 

 No. I24i86e. 13, Interior of the brachial vdve showing 

 divided hinge plate, radulifer crura, and pallial marks, X 2, 

 paratype U.S.N.M. No. 124186b. 14, Same enlarged, X 3, to 

 show crura in greater detail. 15, Same tilted to the side, show- 

 ing crura, X 3- 16, Same tilted to show posterior surface of 

 hinge plate, X 3- Mural limestone, from a small hill 300 yards 

 east of U. S. Highway 80, NWiSW^NEi sec. 36, T. 23 S., 

 R. 25 E., Bisbee Quadrangle, Cochise County, Arizona. 



B. Rectithyris vespertina Cooper, new species 4 



18-22, Pedicle, posterior, brachial, side, and anterior views, re- 

 spectively, of a large specimen, X i, paratyi>e U.S.N.M. No. 

 124194c. 23-27, Pedicle, posterior, anterior, brachial, and side 

 views, respectively, X i. of holotype U.S.N.M. No. 124194b. 

 28, Brachial view, X i, of an immature specimen, paratype 

 U.S.N.M. No. I24i94d. 29, Brachial view of another paratype, 

 X 2, U.S.N.M. No. 124187. 30, 31, Pedicle view of the pre- 

 ceding specimen with window cut in pedicle valve to show 

 loop, X I and X 2, respectively. 32, Interior of a brachial 

 valve showing hinge plate, socket ridges, crural bases, and 

 indistinct adductor scars, X 3. paratype U.S.N.M. No. 124188. 

 33, Interior of a young brachial valve, X 3i showing a loop in 

 an advanced stage, paratype U.S.N.M. No. 124196c. 34, In- 



