242 CRETACEOUS PALEONTOLOGY. 



Cristellaria mamilligera Karrer. 



Plate III, Fig. 8. 



1864. Cristellaria mamilligera Karrer, Novara Exped. GeoL, 



vol. i, pt. 2, p. 76, pi. xvi, fig. 5. 

 1884. Cristellaria -mamilligera Brady, Chal. Rept., vol. ix, p. 



553, pi. Ixx, figs. 17, 18. 

 1898. Cristellaria maimlligera Bagg, Bull. U. S. G. S., No-. 88^ 



p. 56. 



Description. — "Test complanate nearly circular; anterior 

 margin truncate, posterior margin slightly carinate; surface 

 ornamented with a number of large raised ridges and tubercles 

 in the umbilical region ; septa depressed, the depressions partially 

 filled by exogenous material which fo^rms the ridges; chambers 

 large, slightly arcuate, eight or nine in the final convolution; 

 septal plane narrow, surrounded by a definite border; aperture 

 an elongate oval opening surrounded by a crenulated margin. 



"Diameter, 1.74 mm." (Bagg.) 



Remarks. — "This species is very rare in the green marl of 

 Blue Ball, and has not been recognized elsewhere." 



Formation and locality. — Hornerstown marl. Blue Ball 

 (Bagg). 



Geographic distribution. — New Jersey. 



Cristellaria megapolitana (Reuss). 



Plate III, Figs. 9-10. 



1855. Robulina megapolitana Reuss, Zeits. d. Deutsch geol. Ge- 



sell., vol. vii, p. 272, pi. ix, fig. 5. 

 1898. Cristellaria megapolitana Bzgg, Bull. U. S. G. S., No. 88,. 

 P-S7- 



Description. — "Test circular compressed, smooth and glisten- 

 ing, keeled and with more or less definite flange. There are sevem 

 or eight strongly curved chambers apparent externally as raised 

 lines., which are thicker at the umbilicus, but become attenuated 

 toward the peripheral margin. Umbilical disk more or less dis- 

 tinct. Septal plane triangular, with raised border. 



