NO. 5 RHYNCHONELLOID BRACHIOPODS — COOPER 75 



Page 

 the closely crowded costellae separated by narrow, shallow striae. 

 16, Interior of the pedicle valve of another specimen tilted to show 

 apical and dental plates, X 2, hypotype U.S.N.M. 111004b. 17, 

 Posterior of the preceding pedicle valve, X 3, showing large, incom- 

 plete foramen, large teeth, and small disjunct deltidial plates. 18, 19, 

 Respectively anterior and full views of the brachial valve interior 

 showing cardinalia, myophragm, and muscle scars, X 2 , hypotype 

 U.S.N.M. 111004b. 20, Posterior of the preceding specimen tilted to 

 show socket ridge, corrugated socket, and long, slender, curved, 

 radulifer crura with the strengthening ridge on their under or dorsal 

 surface, X 3- 21, Posterior view of the cardinalia of the same speci- 

 men showing socket ridge, small outer hinge plates, and distally 

 flattened crura, X 3- 



Recent, Coal Harbor, Unga Island, Shumagins, Alaska. 



Plate 4 

 Aetheia, Fricleia, Grammctaria, Camarotoechia, and Hemithyris 



A. Aetheia gualteri (Morris) 42 



Fig. 1. Rubber impression of a pedicle valve interior prepared to 

 show the muscle scars and pallial marks, X 2 , hypotype U.S.N.M. 

 369298a (see pi. 9, B). 



Miocene (Duntroon greensand), Otago, New Zealand. 



B. Frieleia halli Dall S3 



Figs. 2, 3. 2, Posterior of a brachial valve, X 6, showing the hinge 

 plates surrounding a plug of the median septum, and the inner hinge 

 plates engulfing the septum, hypotype U.S.N.M. 111021a. 3, Posterior 

 of another brachial valve interior, X 6, with well-preserved cardinalia 

 and elongate adductor scars, and showing inner hinge plates not yet 

 coalesced, hypotype U.S.N.M. 111021b. 



Recent, 559 fathoms, in ooze, 38.4 F., U. S. Fish Commission Sta- 

 tion 2871, off the coast of Washington. 



C. Grammetaria bartschi (Dall) 58 



Figs. 4, 5. 4, Dorsal view of a young but imperfect specimen, X 6 above 

 and X JO below, showing elaborate auriculations on the deltidial 

 plates, paratype U.S.N.M. 274134. 5, Same specimen with brachial 

 valve tilted to show cardinalia and dental plates, X 6, and also show- 

 ing septum united with hinge plates and long curved crura. 



Recent, at 161 fathoms, 57.4 F., on sand, U. S. Bureau of Fish- 

 eries Station 5735, off Jolo, Philippine Islands. 



D. Camarotoechia species 10 



Figs. 6-8. 6, 7, Two views of the posterior part of a silicified brachial 

 valve, X 4, showing crura and median hinge plate welding them to- 

 gether, figured specimen U.S.N.M. 134812c 8, The same specimen 

 tilted to show apical chamber (septalium?) and crural plates, X4 

 (see p. 10). 



Devonian (Norway Point formation), junction French and Truckey 

 roads, SW1/4SW1/4 sec. 4, T. 31 N., R. 8 E., Alpena County, 

 Michigan. 



