Vol. 67.] FORAMINIFEEA, ETC. FROM CTRENAICA. 657 



The Slonta District. 



' Nummulitic limestone, about 5 miles north-east of the shrine 

 of Sidi Mahomet el Homra, east of Slonta.' A compact lime- 

 stone variously coloured, from pale cream on the fresh surface, to 

 reddish brown on the weathered portions. The rock is largely- 

 composed of nummulites, chiefly JV". gizeliensis var. jpachoi De la 

 Harpe, and N. curvupira Meneghini. 



Horizon. — Middle Eocene. 



'A brecciated shell-limestone east of Slonta' (No. 289), with 

 numerous foraminifera, chiefly N. subdiscorbina, De la Harpe. 

 Horizon. — Middle Eocene. 



Echinolampas Limestone (No. 290), north of the Roman Castle, 

 north-west of Slonta, and an iron-stained limestone (No. 288), 

 east of Slonta, are both chiefly composed of Nummulites gizehensis 

 var. lyelli and N. curvispira. 



Horizon. — Middle Eocene. 



Messa and Wadi Jeraib. 



' A yellow limestone (No. 239), with Pecten arcuatus,' Messa, is 

 composed of a small lenticular nummulite. Theform and arrangement 

 of the septa, the number of whorls, and the shape and size of the 

 small central chamber, all point to the species as belonging to 

 the 'planulata' group. De la Harpe regarded Lamarck's species 

 N. planulata as divisible into N. "planulata sensu stricto and 

 N. elegans Sow., and made a third species, N. fraasi, distinguished 

 by its smaller size as compared with the typical microspheric 

 N. planulata : in that feature it also resembles the megalospheric 

 shell of N. elegans. The present form may, therefore, be regarded as 

 a moderately small variety of De la Harpe's N. fraasi. The typical 

 examples of the latter occur in Egypt, according to De la Harpe, 1 

 in the Libyan Stage (Lower Eocene) of El Guss Abu Said, west of 

 Earafrah. In the Nummulitic series of Sinai, from a bed referred 

 either to Middle or to Upper Eocene, I have recorded undoubted 

 examples of N. planulata. 2 It is, therefore, possible that the small 

 variety from Messa is one of the remnant of the planulata type, 

 which ranged upwards as far as the Bartonian. The Cyrenean 

 specimens average 2 millimetres in diameter, and show four to five 

 whorls in transverse section ; they have about six chambers in a 

 quadrant on the fourth whorl. 



'Limestone. Gasr el Migdum ' (No. 189). — A hard, compact, 

 whitish limestone, crowded with well-preserved tests of Nummulites 

 beaumonti D'Archiac. 



Horizon. — Middle Eocene. 



1 Palseontographica, vol. xxx, pt. 1 (1883) p. 162 [8]. 



2 Geol. Mag. dec. 4, vol. vii (1900) pp. 367-68. 



