NO. 5 RHYNCHONELLOID BRACHIOPODS — COOPER 79 



Page 



C. Aphelesia bipartita (Brocchi) 41 



Figs. 13-18. 13, Imperfect brachial valve showing falcifer cardinalia, 

 lack of outer hinge plates, deeply entrenched muscle scars, and short 

 median ridge (myophragm) in full view, X 3, hypotype U.S.N.M. 

 549380a. 14, Same tilted slightly toward the observer to demonstrate 

 absence of outer hinge plates, X 3- T 5, Same in side view, showing 

 the serrated edge and convex outer surface of the falciform crus, 

 X 4- 16, Same in side view, X 3, showing falcifer crura and socket. 

 17, Same tilted to show posterior face of cardinalia with the short 

 socket ridges, lack of outer hinge plates and falcifer crura, X 3- J 8, 

 Same tilted to show cardinalia and serrated distal extremity of crus, 

 X3- 

 Pliocene, Messina, Sicily. 



Plate 9 

 Grammetaria and Aetheia 



A. Grammetaria bartschi (Dall) 58 



Figs. 1-12. 1-4, Respectively dorsal, side, anterior, and posterior views 

 of the holotype U.S.N.M. 239269, X i> showing the rectimarginate 

 commissure. 5, 6, Ventral and dorsal views of the holotype, X 2 . 

 showing the fine radial costellae. 7, Posterior of the pedicle valve of 

 the holotype showing the corrugated teeth, large foramen, and auric- 

 late but broken deltidial plates, X 4- 8, Anterior view of the same 

 pedicle valve showing the vertical dental plates, X 2 - 9, 10, Full and 

 slightly tilted views of the interior of the brachial valve of the holo- 

 type showing the cardinalia with their spinulifer crura, X 2 - n, 

 Partial side view of the cardinalia of the preceding brachial valve 

 showing the strong socket ridge, corrugated socket, and short, slender 

 spinulifer crura, X 4- T2 , Posterior view of the same, brachial inte- 

 rior, X 4, showing socket ridges, small inner hinge plates, and plug 

 closing apical chamber. 



Recent, U. S. Bureau of Fisheries Station 5621, off Jolo Island, 

 Philippines ; 298 fathoms, in Mollucca Pass off Makyan Island. 



B. Aetheia gualteri (Morris) 42 



Figs. 13-22. 13-15, Respectively dorsal, side, and anterior views of a 

 complete specimen, X 1, hypotype U.S.N.M. 89828a. 16, Dorsal view 

 of the preceding specimen, X 2 - 1 7, Posterior of the preceding, X 3. 

 showing the minute foramen and concave deltidial plates. 18, 19, 

 Respectively full and anterior views of the pedicle valve interior of 

 another specimen showing deeply impressed muscle field, X 2 » hypo- 

 type U.S.N.M. 369298a. Note absence of dental plates. 20, Interior 

 of an imperfect brachial valve, hypotype U.S.N.M. 89828b, X 2 » 

 21, Full view of the preceding specimen showing the thick socket 

 ridges, corrugated sockets and thick coalesced inner hinge plates, 

 and long falcifer crura, X 4- 22, Same as preceding, X 4, but tilted 

 to show the slender bladelike falcifer crura, socket ridge, and corru- 

 gated socket. 



Miocene (Duntroon greensand), 1 mile north of Kakanui, north of 

 Otago, New Zealand. 



