14 F. Chapman — Egyptian Foraminifera. 



■? Lower Miocene : from a plateau between Cairo and Suez. 

 Frequent. 



Family NUMMULINID.^. 



Subfamily Polystomellin.i:. 

 NONIONINA, d'Orbigny [1826]. 

 NoNiONiNA BouKANA, d'Orbigny. 



Nonionina Boueana, d'Orbign}'^, 1846 : Foram. Foss. Vienne, p. 108, 

 pi. V, figs. 11, 12. 



This species is represented both by casts and sections in the 

 Egyptian limestone. In the casts the retral processes of the 

 segments are faithfully reproduced, and the umbilical protuberance 

 is well shown. The general form of the test is subcircular, com- 

 pressed, with a rather sharp keel, and numerous narrow chambers. 



Fossil specimens of this shallow- water form have been recorded 

 from the Oligocene of Germany and the Miocene of the Vienna Basin 

 and Southern Italy ; and I have latel}' identified a variety'- of this 

 species in the Miocene of California. 



? Lower Miocene : from a plateau between Cairo and Suez. 

 Common. 



With regard to the age of the foregoing species of foraminifera in 

 the PflieWijm-limestone, should the exact stratigraphical horizon of 

 the rock as Lower Miocene be confirmed, it is of much interest to 

 note the general aspect of the fauna, which strongly tends to confirm 

 this idea, although there are one or two exceptions, such as the 

 presence of Alveolince found by Schwager much lower in the series 

 (Libyan Stage) in Egypt. Since no Nummulites have been observed 

 in our rock-specimens we cannot but regard the occurrence of the 

 Alveolince as indicating an upward range of considerable extent. 



Ll3IEST0NE WITH OpERCULINA, ETC. 



These specimens are labelled Box D, 5, 6, and 7 (1,257), near 

 Erment, right bank of Nile Valley. Captain Lyons considers these 

 beds to be of Pliocene age. The colour of the limestone is of a pale 

 cream to a whitish tint. The foraminifera are not numerous in this 

 rock, but Opercnlina may be detected on the fractured surfaces. In 

 section the rock is a fine granular or crystalline limestone, with 

 some included fragments of a denser and somewhat amorphous- 

 looking limestone scattered through it, especially in specimen D 6. 

 There are also traces of lamellibranch shells and echinoderm spines. 

 The organisms in this rock are deposited very uniformly, their 

 length coinciding with the plane of bedding, so that the sections 

 taken at right angles to one another show the shells cut in two 

 directions, longitudinal and transverse, in the separate slides. The 

 foraminifera are fairly numerous, but rather small, and comprise the 

 genera Textidaria, Glohigerina, Gijpsina, Amphistegina, and Operculina. 



