Plate 21. 



Fig. 1. Frondicularia sagittula, var. lanceolata. X30. Front view of mi- 

 crospheric specimen. D2400. 



2. Frondicularia sagitlula. X30. Front view of megalospheric speci- 



men. D2377. 



3. Frondicularia pygmaca. X200. Front view. After Heron-Allen 



and Earland. 



4. Frnndicularia transluccns. X200. Front view. After Heron-Allen 



and Earland. 



5. Frondiculwria tcncra. X113. a, front view; &, side view; c, aper- 



tural view. After Heron-Allen and Earland. 



6. Frondicularia sidchoHoiiii. X200. Front view. After Heron-Allen 



and Earland. 



7. CristclUiria orbicularis. X30. Side view. D2415. 



199 



