AET. 6 FORAMINIFERA: POLYMORPHINIDAE — CUSHMAN AND OZAWA 109 



Length 1.10-1.50 mm.; breadth 0.45-0.65 mm.; thickness 0.45- 

 0.65 mm. 



Pseudopolymorphina leopolitana is evidently related to P. soldanii, 

 and they have some characters in common, such as inflated chambers 

 and slightly compressed test. 



The present species however, has a much more elongated test, 

 which lacks a triserial arrangement of chambers in its early stages 

 and becomes more or less uniserial in its later stages. 



Reuss separated Polymorphina rudis from Pseudopolymorphina 

 leopolitana by its much larger test and its more nearly uniserial 

 arrangement of chambers. As he noted, Polymorphina rudis is very 

 variable, and we can hardly find two specimens quite alike, therefore 

 it is better to unite Reuss's two species cited above. 



Distribution. — ^Reuss's Polymorphina leopolitana is recorded from 

 the mucronata bed of Lemberg (Cretaceous) and his Polymorphina 

 rudis from Cretaceous tuff of Maastricht, in material from which we 

 found several specimens. 



The figured specimen is from the chalk marl, Saxon Cement Works, 

 Cambridge, England. 



PSEUDOPOLYMORPHINA MENDEZENSIS (White) 



Plate 28, figures 7-9 



Polymorphina mendezensis White, Journ. Pal., vol. 2, 1928, p. 213, pi. 29, 

 fig. 14. 



Test compressed, broadly oval to oblong, rounded at the base; 

 chambers rounded, compressed, arranged at first in a nearly triserial 

 series, becoming biserial, each succeeding chamber removed farther 

 from the base; sutures but little depressed, usually distinct; wall 

 thick, smooth; aperture radiate. 



Length 0.60-0.75 mm.; breadth 0.35-0.45 mm.; thickness 0.20- 

 0.30 mm. 



The present species is very variable in its general outline, some 

 broadly rounded at the end consisting of much compressed chambers, 

 the others much narrower at the initial end as each succeeding more 

 or less inflated chamber is removed farther from the base. 



In spite of the variable shape of the test, the arrangement of cham- 

 bers is rather definite, and is always nearly triserial at the start, be- 

 coming biserial later. A quinqueloculine arrangement of chambers is 

 lacking in this species. 



Distribution. — Pseudopolymorphina mendezensis is very common in 

 the Upper Cretaceous deposits in North America. We have no 

 European specimen representing the present species. 



White recorded it from the base of the Mendez to a point a little 

 above the base of the Velasco. It occurs also in our material from 

 the Navarro formation of Texas in various cores. At the clay pit 3 



