216 Prof. J. W. Gregory — Fossil Echinoidea 



4. The Manaccan Series are repeated on the horizons of Probus 

 and Grarapound, from which they extend across the county to either 

 coast. 



5. The Manaccan Series represent the basement beds of the Lower 

 Devonian, and the Lower Palasozoic groups include Lower Silurian 

 of Caradoc age, but whether the succession is ascending or 

 descending has not been definitely proved, although the evidence 

 suggests a descending sequence. 



Before concluding, it may be remarked that the facts, herein 

 presented, involved such a complete change in the colouring and 

 interpretation of the old geological maps that a special investigation 

 of the evidence on which the conclusions are based was undertaken 

 at the request of the Director by Mr. H. B. Woodward and 

 Mr. Clement Keid. As the result of that investigation they were 

 satisfied that thfe conglomerate was partly derived from the under- 

 lying Veryan and Portscatho Beds, and that those groups, together 

 with the associated Falmouth and Mylor Series, are of Pre-Devonian 

 age. The conclusions, therefore, which form the subject of this 

 communication not only embody the opinions of the author, but 

 command the support of his official superiors of the Geological 

 Survey. 



EXPLANATION OF PLATE XIV. 

 Sketch-map to illustrate the geology of the Manaccan district. 



IV. — Fossil Echinoidea from Sinai and Egypt. 



By J. W. Gregory, D.Sc, F.E.S., F.G.S., 



Professor of Geology, Glasgow University. 



(PLATES X Ais-D XI. 1) 



rpHE collections of Echinoidea described in the following report 



\_ were made by Messrs. Barron, Beadnell, and Hume during 



their work for the Egyptian Geological Survey, and were entrusted 



to me for description by the Director, Captain Lyons, R.E. 



The collections belong to three main series — (1) Cretaceous, 

 (2) Eocene and Miocene, and (3) Pleistocene. The Cretaceous 

 Echinoids come from the massif of Abu Roash, and from Sinai. 

 The specimens from Abu Roash were collected by Mr. H. J. L. 

 Beadnell, and mostly came from the eastern end of the massif near 

 the village of Abu Roash. The best known fossil from this horizon 

 is Coptosoma ahbatei (Gauth.), and the bed fi'om which it comes has 

 been assigned to both the Cenonianian and the Turonian. The 

 sections published by Fourtau^ show that the beds belong to the 

 older part of the Cretaceous massif of Abu Roash ; but he places the 

 C. ahbatei beds in the Turonian^ or Lower Senonian.* Walther, 



1 [Plate XI will appear with the second part of Professor Gregorj-'s paper in the 

 June Number of the Geological Magazine. — Editor.] 



2 Fom-tau: Notes E'ch. foss. E'gypte, 1900, p. 17. 



3 Fourtau : ibid., p. 21 ; and Cret. massif Abu Roash, C.E.., vol. cxxxi (1900). 

 * Fourtau, Revision E'ch. foss. E'gypte: Mem. Inst. E'gypt., vol. iii, fasc. 8 



(1899), pp. 607, 623. 



