354 FORAMINIFERA 



Embryonic chambers bilocular, a larger chamber completely 

 surrounds a smaller one, except at the place where the smaller 

 is attached to the inside of the wall of the larger. The equatorial 

 chambers are spatulate, the outer wall curved or angular. The 

 radial diameter may be relatively long or rather short. 



Middle Oligocene to Miocene. 



Nephrolepidina and Eulepidina intergrade. 



Subfamily Miogypsininae 

 Genus MIOGYPSINA Sacco, 1893 



Plate 56, figures 3, 8; plate 57, figure 2; plate 59, figure 12 

 Genoholotype, Nummulites globulina Michelotti 

 Miogypsma Sacco, Bull. Soc. beige Geol., vol. 7, 1893, p. 205. 

 Heterosteyinnides Cushman, U. S. Nat. Mus. Bull. 103, 1919, p. 97, pi. 

 43, figs. 1-8. 



Test compressed, usually subtrigonal in plan, surface papil- 

 late. Embryonic apparatus excentric in position, in some 

 species apical or subapical, composed of two equal or subequal 

 chambers, around which there are several chambers whose feat- 

 ures are intermediate in character between those of the em- 

 bryonic and those of the usual equatorial chambers. The early 

 chambers may be distinctly spiral in arrangement, later growth 

 mostly on only a segment of the periphery and thereby produc- 

 ing a triangular outline. Equatorial chambers rhomboid or 

 elongate hexagonal, roofs and lateral walls pierced by cribriform 

 perforations. Lateral chambers present, irregular in devel- 

 opment. Pillars developed, terminating in surface papillae. 



Oligocene to Miocene. 



Genus HELICOLEPIDINA Tobler, 1922 



Plate 59, figures 13, 14 

 Genoholotype, Hclicolepidina spiralis Tobler 

 Helicolepidiva Tobler, Ecologae geol. Helvetiae, vol. 17, 1922, pp. 380- 



384, 3 text figs. 

 Helicolepidina H. DouviLLE, Ibid., vol. 17, 1923, pp. 566-569, 2 text figs. 



Test rather small, maximum known diameter about 4 mm., 

 lenticular, slightly asymmetrical with reference to the equatorial 

 plane ; central part arched, sloping to a rather sharp edge. Sur- 



