74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



Page 

 U.S.N.M. 274143a. 4, Partial side view of another individual showing 

 the alate deltidial plates, X 6, paratype U.S.N.M. 274143b. 5, Pos- 

 terior of the specimen shown in figure 4, illustrating the alate deltidial 

 plates, X 8. 6, 7, Respectively anterior and full views of the interior 

 of the pedicle valve, X 6, showing strong dental plates, paratype 

 U.S.N.M. 274143c. 8-1 1, Respectively partial side, full, anterior, and 

 posterior views of the brachial interior of the preceding, showing the 

 long slender maniculifer crura, the short, strongly elevated median 

 septum and the bilobed cardinal process, X 8, paratype U.S.N.M. 

 274143c. 



Recent, Eolis Station 340, 209 fathoms, off Fowey Light, Florida. 



B. Neorhynchia strcbeli Dall 34 



Figs. 12-23. 12-15, Respectively ventral, dorsal, anterior, and side views 

 of a complete specimen, X 2 , showing the sulcate anterior commissure, 

 paratype U.S.N.M. 110741a. 16, 17, Respectively anterior and full 

 views of the posterior pedicle valve, X 4. showing dental plates, corru- 

 gated teeth, and disjunct deltidial plates, holotype U.S.N.M. 110741. 

 18, 19, 21, 22, Respectively full, posterior, anterior, and partial side 

 views of the posterior of the brachial valve of the holotype, X 4. 

 showing broad outer hinge plates, low median ridge, small inner 

 hinge plates, and falcifer crura. 20, 23, Partial anterior and partial 

 side views of the paratype showing socket ridges and short crura, 

 X6. 



Recent, U. S. Fish Commission Station 4721, 2,084 fathoms in 

 Globigerina ooze, 35.1 ° F., mid- Pacific. 



Plate 3 

 Hemithyris 



A. Hemithyris woodwardi (Davidson) 47 



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

 plete specimen, X i> hypotype U.S.N.M. 111083a. 4, Dorsal view of 

 the same specimen, X 2, showing fine radial striae. 5, Beak of a ped- 

 icle valve, X 3> showing large foramen and discrete deltidial plates, 

 hypotype U.S.N.M. 111083b. 6, Interior of the same pedicle valve 

 tilted to show the vertical dental plates, X 2. 7, 8, Respectively ante- 

 rior and full views of a brachial valve showing cardinalia, inconspicu- 

 ous median ridge and muscle scars, X 2, U.S.N.M. 111083c. 9, 

 Posterior view of the same brachial valve showing socket ridges, 

 outer hinge plates, and radulifer crura, X 4- 10, Partial side view of 

 the same brachial valve showing the long slender crura, X 4- n, Pos- 

 terior view of another brachial valve showing the cardinalia and the 

 scars of the diductor muscles at the apex, X 4, hypotype U.S.N.M. 

 111083d. 

 Recent, Hakodate, southern Hokkaido, Japan. 



B. Hemithyris psittacca (Gmelin) 45 



Figs. 12-21. 12-14, Respectively anterior, side, and dorsal views of a 

 complete specimen showing the long beak, X I, hypotype U.S.N.M. 

 111004a. 15, Dorsal view of the preceding specimen, X 2 , showing 



