CYTHERELLA. 



Group I, 

 A, §2. 



9. — sequalis, nov., PI. VI, f. 14, 15, 16. Oblong] 



10. — Tatei, Jones, PL VII, f. 1. Ovate-oblong 



11. — ? inflata (Minister), PL VII, f. 2. Elliptical-ovate 



12. — simplex, J. & K., PL VII, f. 3. Elliptical 



13. — obesa, nov., PL VII, f. 10. Broad-subovate 



14. — sp. (undetermined), PL VII, f. 11. Elliptical- 



oblong ; profile ? 



15. — sp. (undetermined), PL VII, f. 13. Subelliptical J 



16. Cytherella ? rotundata, nov., PL VII, f. 15. Broad-elliptical 



profile not cuneiform. Group I, D ? 



17. — scrobiculata, nov., PL VI, f. 10. Oval-oblong. Surface transversely 



wrinkled; profile cuneiform. Group I, C. 



Surface 

 smooth ; 

 profile not 

 cuneiform, 

 but more or 

 less lanceo- 

 late or 

 narrow-oval J 



Surface punctate; 



18. 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 



Foreign species: 

 Benniei, var. Iowensis, nov., PL VI, f. 17. Elliptical. I, A, § 1. 



— var. intermedia, nov., PL VII, f. 7. Subelliptical. I, A, § 1. 

 regularis, nov., PL VII, f. 6. Elliptical. I, A, § 2. 



— var. nov., PL VII, f. 9. Elliptical ; profile ?. 

 subreniformis, nov., PL VI, f. 18. Elliptical-ovate. I, A, § 2. 

 sp (undetermined), PL VI, f. 19. Elliptical. I, A, § 2 ?. 

 impressa, nov., PL VII, f. 8. Subelliptical. I, A, § 1. 

 Richteriana, nov. (Devonian), PL VII, f. 4. Suboval or ovate. I, A, § 2. 



In figuring the Cytherella we find it convenient to place the valves in an artificial 

 position, with anterior end upwards (instead of to the right or to the left, as the animal 

 would be when moving). Hence the height of the valves seems on the plates to be the 

 breadth, and is so referred to sometimes in the text. The most convex of the two long 

 margins is usually the ventral, and the muscle-spot, as a rule, is nearest to that edge. 



