yS SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



Plate 7 



Plicirhynchia and Aphelesia 



Page 



A. Plicirhynchia plicigera (von Ihering) 52 



Figs. i-ii. 1-3, Respectively anterior, side, and dorsal views of a com- 

 plete specimen showing the long beak and anterior costation, X J » 

 hypotype U.S.N.M. 549346a. 4, Exterior of the dorsal side of the 

 same specimen showing the posterior obscure striation and the strong 

 anterior costation, X 2. 5> Posterior of the same specimen, X 4> show- 

 ing the large foramen, conjunct deltidial plates, and the fine striae on 

 the umbo of the brachial valve. 6, 7, Full and tilted views of interior 

 of a pedicle valve showing the deltidial plates and strong vertical 

 dental plates, X 2, hypotype U.S.N.M. 549346b. 8, 9, Full and tilted 

 views of a fragmentary brachial valve showing cardinal process and 

 incomplete crura, X 2, hypotype U.S.N.M. 549346c. 10, 11, Full and 

 partial side views of the cardinalia of the same brachial valve showing 

 the radulifer crura, thick socket plates, and cardinal process, X 4> 

 Eocene (Patagonian), Mazaredo, Patagonia, Argentina. 



B. Aphelesia bipartita (Brocchi) 41 



Figs. 12-22. 12-14, Respectively side, anterior, and dorsal views of a 

 complete specimen showing small beak, small foramen, and anterior 

 fold, X 1, hypotype U.S.N.M. 549349a. 15, 16, Interior of a pedicle 

 valve in full view and tilted to show the small teeth, small dental 

 plates, oval foramen, conjunct deltidial plates, and muscle field, X 2, 

 hypotype U.S.N.M. 549349b. 17, Posterior of the same pedicle valve, 

 X 4, showing the oval foramen and conjunct deltidial plates. 18-20, 

 Respectively partial side, anterior, and full views of the brachial 

 valve belonging to the preceding specimen (pedicle valve), X 2 » 

 showing the cardinalia. 21, 22, Respectively side and posterior views 

 of another brachial valve, X 3, showing the broad falcifer crura, 

 hypotype U.S.N.M. 549380. 

 Pliocene, Messina, Sicily. 



Plate 8 

 Sphenarina, Aphelesia, and Eohcmithyris 



A. Sphenarina sicida (Seguenza) 62 



Figs. 1-7. 1-5, Respectively dorsal, ventral, anterior, side, and posterior 

 views of a complete and nearly perfect specimen, X ij showing tri- 

 angular form, rectimarginate anterior commissure, and nearly erect 

 beak, hypotype U.S.N.M. 173728. 6, The same specimen enlarged, 

 X 2. 7, Interior of another specimen showing cardinalia, X 10, with 

 their long, slender, spinulifer crura, narrow outer hinge plates, and 

 narrow, elevated socket ridges, hypotype U.S.N.M. 549381a. 



B. Eohemithyris? gettysburgensis Cooper, new species 33 



Pliocene, Messina, Sicily. 

 Figs. 8-12. Respectively anterior, posterior, side, dorsal, and ventral 

 views of a large and complete specimen, X h holotype U.S.N.M. 

 549382. 

 Miocene, on coast 42 miles west of Gettysburg, Washington. 



