264 CRETACEOUS PALEONTOLOGY. 



tO' four convolutions ; septal markings on superior surface appar- 

 ent as fine lines, while the lower surface shows slight depressions 

 of the radiating septa ; last convolution consisting of six or seven 

 chambers; aperture a cleft on the lower side somewhat removed 

 from the margin. 



"Length, 0.45-0.5 mm." (Bagg.) 



Formation cmd locality. — ^Vincentown limesand, Vincentown, 

 Quinton (Bagg). 



Geographic distribution. — New Jersey. 



Pulvinulina micheliniana (d'Orbigny). 



1839. Rotalina truncatulinoides d'Orbigny, Foram. Canaries, 



vol. ii, pt. 2, p. 132, pi. ii, figs. 25-27. 



1840. Rotcdirm micheliniana d'Orbigny, Mem. Soc. geol. 



France, ser. i, vol. iv, p. 31, pi. iii, figs. 1-3. 

 1884. Pulvinulina micheliniana Brady, Chal. Rep., vol. ix, p. 



694, pi. cvi, figs. 1-2. 

 1898. Pulvinulina micheliniana Bagg, Bull. U. S. G. S., No. 88, 



p. 68. 



Description. — ^"Test orbicular, superior surface nearly flat, in- 

 ferior highly convex, with an excavated umbilicus; spire com- 

 planate, with three convolutions; last volution consisting of 10 

 or 12 chambers, angular, separated by straight septal lines below; 

 aperture elongate, slightly removed, from the margin. 



"Diameter, 0.45 mm." (Bagg.) 



Remarks. — "This is not a common species, but was described 

 by Prof. A. E. Reuss under the name Rotalina nitida, which he 

 considered tO' be a young form of Rotalina umhilicata d'Orbigny. 

 Dr. W. B. Carpenter considers that the Rotalina iimbilicata of 

 the Chalk is identical with Rotalina soldanii of the Vienna Ter- 

 tiaries. Prof. PI. B. Brady states that Pulvinulina micheliniana 

 has its isomo>rph in Truncatulina refulgcns, from which species 

 it is distinguished by the more or less excavated umbilicus and 

 the projecting apical margins of the segments. In the Challenger 

 Report, however, Rotalina nitida is not given under the syno- 

 nyms of Pulvinulina michelimana, but Dr. Woodward has so 



