186 



UNITED STATES NATIONAL MUSEUM BULLETIN 216 



% of the umbilical side, and the final chamber of 6. 

 velascoensis comprises J^ to M of the umbilical side, the 

 ornamentation of the umbilical shoulder is more highly- 

 ornamented in 0. velascoensis, and the sutures of the 

 spiral side are limbate, elevated, and beaded. The 

 sutures of 6. acuta are flush with the spiral smrface. 



Types and occureence: Figured hypotypes (USNM 

 P5141a,b) from the Vincentown formation, north bluff 

 of Eancocas Creek, 0.3 to 0.5 miles north of Vincen- 

 town, Bm-lington County, New Jersey. Collected by 

 A. K. Loeblich, Jr., and Norman Sohl. 



Figured hypotype (USNM P5142) from the Salt 

 Mountain limestone, in a limestone sink % mUe north 

 of Salt Mountam, in the NWK NWK, Sec. 34, T. 6 N., 

 K. 2 E., Clarke County, Alabama. Collected by H. T. 

 and A. R. Loeblich, Jr. 



The species also occm-s in the Velasco formation, 

 middle bed at road crossing of arroyo haKway between 

 San Jos6 de las Eusias and Soto la Marina, Tamaulipas, 

 Mexico. Collected by E. Wright Barker. 



Figiu-ed hypotype (USNM P5865) from the Aquia 

 formation, 10 to 13 feet above the base of the exposed 

 section, west bank of Potomac Eiver, near mouth of 

 Aquia Creek, S. 10° E. of Brent Point on U. S. Geologi- 

 cal Survey Nanjemoy Md.-Va. Quadrangle, 1:62,500, 

 1913, reprinted 1945. Collected by A. E. Loeblich, 

 Jr., and Eichard A. Page. 



Globorotalia aequa Cushman and Renz 



Plates 46, Figtjbbs 7a-8o; 50, Figttres 6a-c; 55, Figures 



8a-o(?); 59, Figtjkes 6a-c; 60, Figures 3a-c; 64, Figures 



4a-c 



Globorotalia crassata (Cushman) var. aequa Cushman and Renz, 



Contr. Cushman Lab. Foram. Res., vol. 18, pt. 1, p. 12, pi. 



3, figs. 3a-c, 1942. 



Test free, trochospiral, spiral side flat or slightly- 

 convex, umbilical side strongly convex, peripery sharply 

 angled with a narrow keel, peripheral outline strongly 

 lobulate; chambers increasing rapidly in size, lunate in 

 spiral view, rhomboidal and truncate in section, 

 sharply angled at the mnbilical shoulder around a 

 relatively -wide and open umbflicus, lower margin of 

 final chamber conmaonly constricted against the 

 earlier whorl, the chamber expanding above in -width, 

 sutiu-es distinct, gently curved, slightly thickened and 

 beaded on the spiral side, each chamber being at- 

 tached somewhat below the level of the anterior margin 

 of the preceding one, giving the appearance of a de- 

 pression at the sutiu-es, sutures radial and constricted 

 on the umbilical side; wall calcareous, finely perforate, 

 keel and sutiu-es on spiral side thickened and nodose, re- 

 mainder of surface somewhat granular in appearance 

 although final chamber may be somewhat smoother; 

 aperture interiomarginal, extraumbilical-umbilical, in 

 well preserved specimens -with a thin and delicate 

 subtriangular lip. 



Hypotypes range from 0.30 to 0.40 mm. in diameter. 



Eemaeks: Globorotalia aegua differs from O. rex 

 Martin in having higher chambers, fewer per whorl, 



more lobulate periphery, more angular umbilical 

 shoulder and -wider umbilicus, more spinose keel and 

 pustulose surface. The spiral side of 6. rex is flat and 

 sutures flush, whereas in 0. aegua the chambers are 

 somewhat imbricated in appearance, and the sutures 

 thickened and nodose. 



Earely, a specimen may show a dwarfed instead of 

 the more usual large and prominent final chamber, 

 such as that sho-wn on plate 55, figure 8. This final 

 chamber somewhat resembles the bullae developed by 

 some orbulinids, in the thin wall, lessened ornamenta- 

 tion and tendency to cover the previous aperture. 

 The aperture of this final chamber is nearly imibihcal 

 in position. However, it retains the characteristic 

 surface of the species, and the final chamber is visible 

 on both the spiral and umbilical sides. Typical simple 

 buUae, such as foimd in Catapsydrax are distinctly 

 umbilical in position, completely covering the former 

 apertm-e and the umbilicus, and commonly lack the 

 ornamentation of the true chambers. The small 

 chamber here shown is thus imdoubtedly only a senile 

 development of the specimen and not of generic or 

 specific importance. 



Types and occ-cjerence: The hypotype (USNM 

 P5888) figured on plate 55 is questionably referred here. 

 It is from the Vincentown limesand, north bluff of 

 Eancocas Creek, 0.3 to 0.5 mile north of Vincentown, 

 Burlington Coimty, New Jersey. Collected by A. E. 

 Loeblich, Jr., and Norman Sohl. 



Figured hypotype (USNM P5889) from the Homers- 

 town formation, north bank of Shingle E\m, a tributary 

 to Crosswicks Creek, 1.0 mile north of New Egypt, 

 Monmouth County, New Jersey. Collected by A. E. 

 Loeblich, Jr., and Norman Sohl. 



Figured hypotype (USNM P5894) from the Velasco 

 formation, middle bed at road crossing of arroyo 

 halfway between San Jos6 de las Eusias and Soto la 

 Marina, Tamaulipas, Mexico. Collected by E. Wright 

 Barker. 



Figured hypotype (USNM P5125) from the Aquia 

 formation, 15 to 17 feet above the base of the exposed 

 section, west bank of Potomac Eiver, near mouth of 

 Aquia Creek, S. 10° E. of Brent Pomt on U. S. Geo- 

 logical Survey Nanjemoy Md.-Va. Quadrangle, 1:62,500, 

 1913, reprinted 1945. 



Figured hypotype (USNM P5863) from the Nanafalia 

 formation, south vaUey wall of Shoal Creek, 5.5 miles 

 southeast of Camden, along the Camden-Fatama road, 

 Wilcox County, Alabama. CoUected by A. E. Loe- 

 blich, Jr. 



Figured hypotypes (USNM P5864a, b) from the 

 Coal Bluff marl member of the Naheola foraaation, in 

 creek bottom, just west of store at Caledonia, about 

 Yi mile south of the center of Sec. 29, T. 11 N., E. 10 E., 

 Wilcox County, Alabama. Collected by F. Stearns 

 MacNeil. 



The species was originally described from the 

 Soldado formation (Paleocene) of Trinidad, B. W. I. 



