Plate 51. VINCENTOWN CHILOGUEMBELINA AND GLOBIGERINA 



(All figures X 145) 



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Figures la-3. Chiloguemhelina crinita (Glaessner) 178 

 la, 2a, 3, Side views of hypotypes (USNM 

 P511Sa-c), showing slightly twisted biserial 

 test, lb, 2b, Edge views, with slightly asym- 

 metrical aperture bordered by an apertural 

 flange, instead of the symmetrical and open 

 arched aperture typical of true Heterohelix. Ic, 

 2c, Top views, showing how the bordering 

 flange directs the apertural opening toward the 

 side rather than the edge of the test. 

 Figures 4a-Sc. Globigi-rina aquiensis Loeblich and 180 

 Tappan, new species 



4a, 5a, Spiral views of paratypes (USNM 

 PS841a, b), showing few chambers rapidly in- 

 creasing in size. 4b, 5b, Umbilical views, show- 

 288 



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Ing small umbilical aperture. 4c, 5c, Edge views, 

 showing inflated tests, and variation in height of 

 spire. 

 Figures 6a-9c. Globigerina spiralis Bolli 



Hypotypes (USNM P5121a-d); all figures a, 

 spiral side; b, umbilical side; C, edge view. 6, 

 Large hypotype with four chambers in final 

 whorl and a buUa-like final chamber, showing a 

 tendency to obscure the umbilical region. 7, 8, 

 Typical hypotypes showing variation from 4 to 

 S/2 chambers in the final whorl, characteristic 

 many-whorled spire, spinose surface and open 

 umbilical aperture. 9, Hypotype with small 

 final chamber that has an almost extraumbilical 

 aperture. 



182 



