182 



UNITED STATES NATIONAL MUSETJM BTJLLETESr 216 



wards on the spiral side, radial on the umbilical side; 

 wall calcareous, surface finely spinose, the spines most 

 prominent in the umbilical region, an occasional speci- 

 men has a smaller final chamber which is thin-walled 

 and nearly smooth; apertiu-e interiomarginal, umbilical, 

 in some specinaens showing a tendency to extend some- 

 what to an extraumbUical position, with apertm-es of 

 earlier chambers aU remaining open into the umbilicus. 



Hypotypes range from 0.28 to 0.48 mm. in diameter, 

 and 0.20 to 0.35 mm. in thickness. 



Remarks: Originally placed in Globigerina, this spe- 

 cies was placed in Globorotalia by BoUi (1957, p. 79). 

 However, the early umbilical position of the aperture, 

 inflated chambers, rounded periphery, and coarsely 

 spinose sm-face all show a stronger relationship to Glo- 

 bigerina (and the type species Globigerina bulloides) than 

 to Globorotalia (typified by Globorotalia tumida). The 

 gradual migration of the aperture from completely um- 

 bilical to a somewhat extraumbilical position can be 

 found in nearly every species of Globigerina, if a large 

 suite of specimens is examined. This species is closest 

 in appearance to Globigerina soldadoensis Bronnimann, 

 which BoUi did leave in Globigerina, although even the 

 holotype of this species has an asjrmmetrical aperture. 



Bolli (1957, p. 72) recorded Globigerina gravelli Bron- 

 nimann as occurring in Trinidad throughout the lower 

 Eocene part of the Lizard Springs formation, although 

 the holotype of Bronnimann's species was from the 

 lower Lizard Springs formation (Paleocene, Globorotalia 

 velascoensis zone, sample Rz 287). The specimen fig- 

 ured by Bolli from the upper Lizard Springs formation 

 (of lower Eocene age) as well as the holotype of gravelli 

 would both easily fall within the variation of Globoro- 

 talia mckannai White at its type locality (Velasco 

 formation of Mexico, Globorotalia velascoensis zone) . 



Globigerina mckannai shows a tendency to develop 

 the somewhat truncate chamber form typical of Glo- 

 boguadrina, but differs in lacking the toothlilce apertural 

 flaps. This appearance also suggests a relationship 

 with the Orbulinidae, rather than the Globorotaliidae. 



Globigerina soldadoensis Bronnimann commonly has 

 fewer chambers per whorl, a more rapid increase in 

 chamber size, and thinner chambers. 



Specimens of G. esnehensis identified by S. E. Nak- 

 kady show it to be synonymous with the present species. 



Types and occurrence: Figured hypotypes (USNM 

 P5119a,b) from the Vincentown formation, along north 

 bluff of Rancocas Creek, 0.3 to 0.5 miles northwest of 

 Vincentown, Burlington County, New Jersey. Col- 

 lected by A. R. Loeblich, Jr., and Norman Sohl. 



Figured hypotype (USNM P5120) from the Aquia 

 formation, 14 to 16 feet above base of exposm-e, west 

 bank of Potomac River, near mouth of Aquia Creek, 

 S. 10° E. of Brent Point, on U. S. Geological Survey 

 Nanjemoy Md.-Va. Quadrangle, 1:62,500, 1913, re- 

 printed 1945. CoUected by A. R. Loeblich, Jr., and 

 Richard A. Page. 



Figured hypotype (USNM P5833) from the Salt 

 Mountain limestone, in a limestone sink, % mile north 

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



R. 2 E., Clarke County, Alabama. CoUected by H. T. 

 and A. R. Loeblich, Jr. 



Lectotype (Colmnbia Univ. 19878), here designated, 

 from the Velasco formation, Columbus Station on the 

 Tampico-Monterey railroad line, Mexico. 



Figured hypotypes (USNM P5884a,b) from the 

 Velasco formation, middle bed at road crossing of arroyo 

 halfway between San Jos6 de las Rusias and Soto la 

 Marina, Tamaulipas, Mexico. Collected by R. Wright 

 Barker. 



Globigerina cf. G. soldadoensis Bronnimann 



Plate 53, Figures 4a-c 



Test free, of medium size, globose, periphery broadly 

 rounded; chambers increasing rapidly in size, only the 

 3K chambers of the final whorl visible around the deep 

 and open umbUicus of the umbilical side; sutures 

 distinct, slightly depressed, somewhat oblique on the 

 spiral side, radial on the mnbUical side; wall calcareous, 

 finely perforate, surface covered with short blunt 

 spines, aperture interiomarginal, mnbilical, or extend- 

 ing slightly to an extraumbilical-umbilical position. 



Figured specimen 0.33 mm. in diameter. 



Remarks: This form differs from typical G. soldado- 

 ensis Bronnimann in being more globose, with more 

 evenly rounded chambers and less incised sutm-es. It is 

 somiewhat similar to the associated 6. mckannai White, 

 but differs in having fewer chambers per whorl, a more 

 broadly rounded periphery and a flatter spire. 



Types and occurrence: Figured specimen (USNM 

 P5130) from the Vincentown formation, north bluff of 

 Rancocas Creek, 0.3 to 0.5 miles north of Vincentown, 

 Burlington County, New Jersey. Collected by A. R. 

 Loeblich, Jr., and Norman Sohl. 



Globigerina spiralis Bolli 



Plates 47, FigubesS a-c; 49, Figures 3 a-c; 51, Figures 6 ar-9 c; 

 53, Figures 3 a-c 



erina spiralis bolli, U. S. Nat. Mus. Bull. 215, p. 70, 

 pi. 16, figs. 1&-18, 1957. 

 Globigerina cf. ouachitaensis Howe and Wallace, shifflbt, 

 Maryland Dep. Geol., Mines and Water Resources Bull. 3, 

 p. 71, pi. 4, figs. 11-13, 1948. 



Test free, the high trochospiral coiling resulting in a 

 nearly globular test; chambers globular, increasing 

 rapidly in size, those of the 2 to 3 whorls all visible on 

 the spiral side, only the 4 to 6 chambers of the final 

 whorl visible on the umbUical side, umbilicus open, rare 

 specimens may have the umbilicus nearly closed (pi. 61, 

 fig. 6); sutures distinct, depressed; waU calcareous, 

 perforate, surface finely to moderately spinose, most 

 prominently so in the umbilical region ; aperture a broad 

 umbilical interiomarginal arch in the fimal chamber, 

 those of previous chambers also remaining open into 

 the umbilicus. 



Greatest diameter of hypotypes ranges from 0.18 to 

 0.38 mm. 



Remarks: Globigerina spiralis Bolli is distinguished 

 by the globular test and the extremely prominent spire, 



