342 FORAMINIFERA 



floridana prepared to show the embryonic and equatorial cham- 

 bers. The embryonic chambers are typically reniform. The de- 

 gree of degeneration of the radial chamber-walls varies and is 

 not of generic significance. There is variation in the relation of 

 the chamber walls of adjacent rings, they may alternate or they 

 may be in alignment. I examined many specimens and figures of 

 Discocyclina with reference to this feature. Even the original 

 figures of Giimbel {op. sup. cit.) show variation. This feature 

 does not furnish characters of even specific value. Therefore, 

 in my opinion, Pseudophragmina is a synonym of Discocyclina. 

 The species I described as Orhitochjpeus (?) cristensis, (Bull. 

 Geol. Soc. Amer., vol. 35, 1924, p. 814, pi. 36, fig. 8) , I now con- 

 sider to belong to Discocyclina. The receipt of additional speci- 

 mens has made possible the examination of the embryonic cham- 

 bers, which, although they are somewhat different from those of 

 Discocyclina that I have previously examined, do not appear suf- 

 ficiently difi'erent to warrant reference to another genus. 

 Orbitoclypeus according to Silvestri represents the last evolu- 

 tionary phase of Spiroclypeus (Boll. Soc. geol. Ital., vol. 26, 1907, 

 p. 59.) 



EXPLANATION OF PLATE 57 



Fig. 



1. Lepidocijclina (Le^ndocycUna) inortoni Cushman. X 80, (After 



Vaughan). Part of horizontal section to show perforations in the 

 chamber roofs and floors and details of the chamber walls. 



2. Miogypsina cushmani Vaughan. X 80. (After Vaughan). Part of 



a horizontal section to show perforations in the roofs and floors of 

 the chambers and details of the chamber walls. 



3. Lepidocyclma (Polylepidina) proteiforniis Vaughan. X 16. (After 



Vaughan). Section in median plane of megalospheric specimen. 



4. Orbitoides media (d'Archaic). X IC (After Vaughan). Showing 



quadrilocular embryonic apparatus surrounded by a common thick 

 wall. 



5. LepidocycUna (Nephrolepidma) undosa Cushman. X IG. (After 



Vaughan). Horizontal section through embryonic and meridional 

 chambers. 



6. Lepidocyclma (LepidocycUna) parvnia Cushman. X 8. Vertical 



section. 



7. LepidocycUna (Enlepidina) favosa Cushman. X 16. (After Vaughan). 



Horizontal section through embryonic and meridional chambers. 



