98 THE FOSSIL ECHINOIDEA 



of the Egyptian Nummulitic are not found in the Kanikot series, or are sparsely repre- 

 sented in species. 



Thus the genera Salenia, CypTiosoma, Acanthechinus, the Teranopleuridae, the genera 

 Euri/pneustes and JEolopneustes, Phylloclypeus, Plesiolampas, JEcUnantJius, Eolampas, 

 Paralampas, Cassidulus, Eurhodia, Neocatopygus, Prenaster, and Metalia (in all 18 

 genera of the Ranikot series out of its -26 genera) are not found in Egypt. 



The Egyptian fauna is rich in species of Echinolampas and Macropneusfes, Hemi- 

 spatangus and Euspatangus. It contains the well-known genera ConocJypeus, Ambly- 

 pygus, Orthopsis, Micropsis, Sismondia, and Echinocyamus ; and there is a fine group 

 of Schizasters and Linthias. There are two Linthias in the Ranikot series and a 

 Schizaster ; but all the above-mentioned genera are absent. 



The generic distribution in the two areas, although plainly Eocenic, is very different. 

 The absence of the genera Echinolampas and Amblypygus in the Ranikot series is very 

 suggestive, especially as they appear in the succeeding Khirthar group. 



The position of the Egyptian beds, or the Mokattam series, which have yielded the 

 Echinoidea is stated by de Loriol to be on the horizon of San Giovanni Ilarione in 

 the Vicentin, and of the Eocene of the Canton de Schwytz. These are the equivalents 

 of the Calcaire grossier of Paris. But the succession of beds in Egypt appears to be, 

 from the results of the works of Fraas, Zittel, d'Archiac, and Delanoue as follows : — 

 On the top, beds with Ostrea flabellwla, and below it the shale containing the Echi- 

 noidea described by de Loriol. Still lower are beds with Atruria ziczac, and of the 

 age of the London Clay. Zittel has discovered under the Mokattam series, which he 

 considers Lower Nummulitic, a series which he calls the Libyan ; and it includes the 

 Atruria-ziczac horizon. It rests on Cretaceous sandstones. 



Are the Ranikot beds of the same geological age as the Mokattam series, or do they 

 belong to Zittel's inferior stage, which would seem to range through the age from the 

 Chalk to the London Clay inclusive ? The homotaxis of the genera of the Ranikot 

 series is not that of the Mokattam age ; and this last has greater affinities, so far as its 

 distribution of genera is concerned, with the Khirthar strata above the Ranikot series. 



The Fossil Corals of the Ranikot series were shown to belong to 50 species 

 (' Fossil Corals and Alcyonaria of Western Sind,' Palaeont. Indica, series xiv. p. 38), 

 and that only 7 of these were identical with European species from the zones of 

 Nummulites planulatus and CeritMum giganteum. It is a remarkable fact that the 

 Nummulitic Echini of Kach have greater affinities with the Egyptian fauna than with 

 that of Ranikot, and the genus Echinolampas predominates with Macropneustes. 



Laube and Dames have given the data for comparing the fauna of Echinoidea of 

 the Vicentin Eocene. In the lowest deposits of Monte Postale and Monte Spilecco there 

 are two genera, Cyclaster and Ccelopleurus, and also Echinolampas, which are not found 

 in the Ranikot, but which are in abundance in higher ho^rizons in Sind. At San Giovanni 

 Ilarione there are the genera Cidaris, Porocidaris, Cyphosoma, Pyrina, Echinocyamus, 

 Amblypygus, Nucleolites, Pygorhynchus, Bariona, Echinolampas, Oviclypeus, Conoolypeus, 



