IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 211 



1953 Acarinina psendotopilensis Subbotina (pars) : 227, pi. 21, figs. 8a-gc ; pi. 22, figs, za-y, 

 non pi. 22, figs. la-c. 

 ? 1953 Globigerina varianta Subbotina (pars) : 63, pi. 3, figs. 8a-c only ; non pi. 3, figs. 5a-yc, 

 ioa-i2c ; pi. 4, figs. la-y ; pi. 5, figs. ia-y. 

 1959 Globigerina esnaensis Le Roy ; Nakkady : 461, pi. 3, figs. 2a-c. 

 i960 Globorotalia pseudotopilensis (Subbotina) Said : 283, pi. 1, figs. 3a— c. 

 ? 1960a Globorotalia wilcoxensis Cushman & Ponton ; Berggren : 97, pi. 13, figs. },a-^c. 



1961 Globorotalia esnaensis (Le Roy) Said & Kerdany : 328, pi. 1, figs. 6a-c. 



1962 Globorotalia esnaensis (Le Roy) ; Gartner & Hay : 563-564, pi. 2, figs. \a-c. 



Description. Test large, globigerine, umbilico-convex, coiled in a very low 

 trochospire ; dorsal side slightly flattened especially in the early part ; ventral side 

 highly convex and strongly inflated ; equatorial periphery roughly quadrate, 

 distinctly lobate and coarsely spinose ; axial periphery broadly rounded ; chambers 

 on the dorsal side about 9, arranged in 2 dextrally coiled whorls; the initial chambers 

 are small, inflated, globigerine, and are masked by the surface rugosity ; the last 

 whorl is composed of 4 large chambers which increase so rapidly in size that the last, 

 which is very strongly inflated, constitutes about \ of the test ; the first 3 chambers 

 in this whorl are roughly rectangular and arcuate , while the last is subglobular on 

 the dorsal side ; on the ventral side the chambers are 4, large, subglobular, and 

 strongly inflated ; sutures on dorsal side straight, radial and depressed ; on ventral 

 side they are straight, radial, and strongly incised ; umbilicus medium-sized, 

 shallow and open ; aperture an elongate, low arch, interiomarginal, extraumbilical- 

 umbilical ; wall calcareous, finely perforate ; surface rough, nodose or rather 

 coarsely spinose especially on the dorsal side and along the periphery. 



Dimensions of described specimen. 



Maximum diameter = 0-50 mm. 



Minimum diameter = 0-40 mm. 



Thickness = 0-28 mm. 



Main variation. 



1. Chambers 8-10, most commonly 9, arranged in 2-2 1 whorls which are generally 



dextrally coiled, but sinistral forms also occur ; (of 470 specimens studied, 

 180 coiled sinistrally) . 



2. The last whorl is composed of 4-5 chambers, but 4 is most common. 



Remarks. Globorotalia esnaensis was first described by Le Roy, (February 1953) 

 as Globigerina esnaensis n.sp. from the Esna shales of the Maqfi section, Farafra 

 Oasis, Egypt. Subbotina (November 1953) described as Acarinina pseudotopilensis 

 n.sp. a form which conforms well with Le Roy's original description and figures of 

 G. esnaensis, and is thus considered a junior synonym. In the same work, Subbotina 

 figured and described as Globigerina varianta n.sp., a form which probably belongs to 

 G. esnaensis (see synonymy). 



Loeblich & Tappan (1957a) removed this species to the genus Globorotalia, because 

 of the extraumbilical-umbilical position of its aperture, but their figures are different 

 from the holotype of G. esnaensis. 



The forms described as Globorotalia pseudotopilensis (Subbotina) by Loeblich & 

 Tappan (1957a), Berggren (1960a) and Reyment (i960) are different from G. esnaensis 



