JR. BuUen Neidon — Egyptian Lower Tertiary Shells. 531 



only difficulty arises in reference to its generic determination. It 

 will be best to place it provisionally in the genus Coelacanthus, from 

 which the parts described diflfer in no essential respect ; while the 

 minor characters of form and ornamentation just enumerated readily 

 separate it from all known species.^ It must thus be recorded for 

 the present as Ccelacanthus Kayseri. The only well-known Lower 

 Carboniferous species, C. Huxleyi,'^ differs very considerably from 

 this form in the feebleness of its ornamentation ; but a detached 

 gular plate from the Lower Carboniferous Limestone of Armagh 

 exhibits a nearer approach to it.^ 



The type-specimen of Coelacanthus Kayseri was found by Dr. von 

 Koenen in the lower part of the Upper Devonian at Miillenborn, 

 near Gerolstein ; and it is interesting to add that in the same 

 formation and locality he met with a second small fossil, which 

 he provisionally regards as a scale of Hhizodopsis,^ another Car- 

 boniferous genus. I am, however, convinced that this supposed 

 scale is much too thick and bony to be referred to the latter 

 fish, and its systematic determination must remain as entirely 

 problematical, 



11. — Notes on some Lower Tertiary Shells from Egypt. 



By R. Bulled Newton, F.G.S. 



(PLATES XIX AND XX.) 



THE Tertiary shells referred to in this paper constitute a portion 

 of the Egyptian collection of fossils sent to the British Museum 

 for description by Capt. H. G. Lyons, E.E., F.G.S., Director of the 

 Geological Survey of Egypt. 



Among the principal writers on this subject may be mentioned 

 the names of Bellardi, Fraas, and Mayer-Eymar ; the contributions 

 of the last-mentioned having mostly appeared in the Journal de 

 Conchyliologie (Paris), Vierteljahrsschrift Naturforschenden Gesellschaft 

 Zurich, and in Zittel's memoir on Egypt contained in the Palaeonto- 

 graphica for 1883. For the latest information on the distribution 

 of the Tertiary rocks of Egypt we must consult Captain Lyons' 

 monograph in the Quarterly Journal of the Geological Society of 

 London, vol. l (1894:), "On the Stratigraphy and Physiography 

 of the Libyan Desert of Egypt." 



The specimens have been obtained from several localities, chiefly 

 in the neighbourhood of the Nile, such as Minyeh, Esna, Assiout, 

 Wadi Faregh, etc. ; and the various horizons represented include — 

 (?) Oligocene. 



Middle Eocene (Mokattam Series). 

 Lower Eocene (Libyan Series). 



^ A synopsis is given in A. S. "Woodward's " Catalogue of Fossil Fishes in the 

 British Museum," pt. ii (1891), pp. 399-408. 



* E. H. Traquair, Trans. Eoy. Soc. Edin., vol. xxx (1881), p. 20, pi. i, fio-s. 

 1-4 ; A. S. "Woodward, op. cit., p. 407, pi. xiv, fig. 1. 



3 J. W. Davis, Trans. Eoy. Duhlin Soc. [2], vol. i (1883), p. 524, pi. ixiii 

 fig. 12. 



* A. von Koenen, loc. cit., 1895, p. 29, pi. ii, fig. 2 [Rhizodopsis dispersa). 



