MAKVI.AM) (IKOI.OdlCAL SURVEY 241 



ing of six cluunbors, largest and most distinct at oral end, hliinlly acu- 

 minate, aperture on incurved side of final chajnber. 



Brady says of this form, "Individual specimens vary a good deal in 

 contiini'. and also as to the nundx-r and degree of development of the 

 superlicial ril)s; but the stout proportions of the shell, its subcylindrical 

 form, and comparatively slight curvature, the inflated character of the 

 later chambers, and (he uiaigiual aperture, are generally sufficient to 

 distinguish it from costato varieties of Vaf/inuUiia and CrisleUaria. 

 The test is usually more or less compressed just at the commencement, 

 and occasionally presents a sharp or even subcarinate edge at the aboral 

 end, but more frequently the margin is rounded from the beginning." 



It is found in many parts of the Xorth Atlantic at depths ranging 

 from 370 to 1240 fathoms, from the South Atlantic at still greater 

 depths, from the Mediterranean, and from the Adriatic. Save a few 

 specimens found at 150 fathoms of? the coast of New Zealand, it has not 

 been observed in any portion of the Pacific ocean, in the Southern 

 ocean or the Eed Sea. 



Occurrence. — Aquia Foematiox. Upper Marlboro. 



Collection. — Maryland Geological Survey. 



Genus CRlSIELLARlA Lamarck. 



Ceistellaeia gibba d'"Orbigny. 



Plate LXIII, Fig. i. 



Crist ell aria gibba d'Orbiguy, 1839, Foram. Cuba, p. 63, pi. vii, tigs. 20, 21. 

 Cristellaria excisa Bornemann, 1855, Zeitscbr. d. deutscb. geol. Gesell., vol. vii, 



p. 328, pi. xiii, figs. 19, 20. 

 Cristellaria piilchella Reuss, 1S62, Sitzungsb. d. k. Akad. Wiss. Wien, vol. xlvi, 



p. 71, pi. viii, tig. 1. 

 Robulina concinna Reuss, 1863, Sitzungsb. d. k. Akad. Wiss. Wien, vol. xlviii, p. 52, 



pi. V, tig. 58. 

 Cristellaria gibba Bagg, 1898, Cret. Foram. New Jersey, Bull. 88, U. S. Geol. Survey, 



p. 56. 



Description. — Test oblong, biconvex, smooth, subcarinate, narrow; 



chambers few (seven or eight), slightly arcuate, separated by distinct 



septa; aperture marginate. Length (Cretaceous), 1.3 mm.; breadth, 0.87 



mm. The septal face is rather sharply cut of! from the whole surface 



and this feature separates it from Cristellaria acut auricular is which it 

 16 



