IN THE ESNA-IDFU REGION, NILE VALLEY, EGYPT 245 



G. velascoensis parva differs from G. velascoensis velascoensis in having fewer cham- 

 bers per test (7-9 \), and fewer chambers in the last whorl (3f-4§) ; these are typically 

 crescentic, much larger and increase much more rapidly in size as added. It is also 

 distinguished by its slightly narrower umbilicus and distinctly lobate periphery. 



Rey's holotype is not clearly figured, lacks the side view, and is incompletely 

 described. However, he stated that the variety only differs from the central type 

 in that the number of chambers is reduced to 3, 4 or 5 in the last whorl. This 

 confirms its identity with the present subspecies, although forms with 5 chambers 

 are here considered to belong to the central type. 



Bolli & Cita (1960&) studied paratypes of G. velascoensis parva from Morocco and 

 hypotypes from northern Italy, and their figured form conforms well with the 

 specimens here studied. 



Kiipper (1961) described as G. (T.) acuta Toulmin, a form which appears to be 

 G. velascoensis parva Rey. 



Aubert (1963) described as G. velascoensis var. parva from the Paleocene of 

 Morocco, a form which most probably belongs to G. occlusa Loeblich & Tappan. 

 However, he confused the latter species with superficially similar forms and thus 

 extended its range to the Lower Lutetian. On the other hand, he described as 

 G. acuta Toulmin, which he restricted to the Paleocene only, a form which most 

 probably belongs to the present subspecies. 



Globorotalia velascoensis parva was lumped in the past with G. velascoensis velasco- 

 ensis (Cushman) although their morphological features and stratigraphical distribu- 

 tion warrant their separation. Hamilton (1953), for example, figured under G. 

 velascoensis (Cushman), forms which represent the central type and also its two 

 subspecies (see synonymy). 



G. velascoensis parva Rey is believed to have evolved from G. velascoensis velasco- 

 ensis (Cushman) as suggested by their morphological features and stratigraphical 

 ranges. 



Hypotype. P.45639. 



Horizon and locality. Figured specimen, from sample No. 41, Gebel Owaina 

 section. 



Stratigraphical range. The subspecies was first described by Rey (1955) 

 from the Paleocene of Morocco, and was recorded (as G. acuta) from the Paleocene of 

 the same country by Aubert (1963), who wrongly extended its range to the Lower 

 Lutetian. It was also recorded from the .Mid-Pacific seamounts (Hamilton 1953), 

 the Paleocene of Italy (Bolli & Cita 1960a, b ; Luterbacher & Premoli Silva 1962 ; 

 and Premoli Silva & Palmieri 1962), and from the Paleocene of Vienna Basin (Kiipper 

 1961). 



In the Esna-Idfu region G. velascoensis parva appears in the lower part of the 

 Upper Paleocene G. velascoensis Zone, shortly after the first appearance of G. velasco- 

 ensis velascoensis. It floods this zone together with the central type, but fades out 

 gradually upwards in the section dying out completely in the G. aequa-G. esnaensis 

 Subzone. 



