38 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



[Dec. 5, 



The following communications were read : — 

 1. A Description of some Echinodermata from the Cretaceous 

 Rocks of Sinai. By P. Martin Duncan, M.B. Lond., Sec. G. S. 



Contents. 



1. Introduction. 



2. List of the species of Echinoder- 



mata. 



3. List of the species already de- 



scribed. 



4, List of the species from South- 



eastern Arabia. 



5. Remarks on the species, their per- 



sistence and variability. 



1. Introduction. — The existence of Cretaceous rocks in the district 

 of Sinai has been surmised for several years ; but hitherto the cor- 

 rect geological denomination of the strata has not been ascertained. 

 They have been simply termed Cretaceous ; and, owing to the scarcity 

 of fossils, they have not been correlated with any of the Asiatic 

 formations. 



An examination of the series of Echinodermata collected by the 

 Eev. F. W. Holland, from the limestones of Wady Mokatteb and Wady 

 Badera*, readily decides the geological age of the rocks, and enables 

 them to be correlated with those red limestones in South-eastern 

 Arabia whose fossils were described in a former communication f- 



Had these Sinaitic Echinodermata been in my possession during 

 the preparation of that communication, their study would have made 

 it much more complete ; but coming before my notice now, their ex- 

 amination presents several tests in reference to the correctness of my 

 conclusions. It is satisfactory that this examination should streng- 

 then all those conclusions, and that it should determine the presence 

 of the same zone of Echinodermal hfe in Southern India, on the 

 Nerbudda, in South-eastern Arabia, Sinai, Egypt, Algiers, and in 

 North- western Europe. Moreover the remarks made upon the varia- 

 bility of the species described in the former communication receive 

 additional strength, and the correctness of placing all the localities 

 formerly noticed, with the Sinaitic chalk, in the Middle Cretaceous 

 series, or in that which comprises the Cenomanien and Turonien 

 stages, becomes apparent. 



The few Echinodermata described by Desor and d'Orbigny from 

 Sinai appear to be peculiar to that region ; but all those collected by 

 Mr. Holland are well-known forms, and are characteristic of the 

 typical Upper Greensand of Erance, England, and Ireland. 



The facies of the collection is that of the South-eastern Arabian and 

 Bagh series; so that nothing can be more complete than the correspon- 

 dence of the united Asiatic Echinodermata with those of the zones of 

 Pecten asper, Py gurus lampas, Scaphites cequalis, Ammonites navi- 

 cularis and Ostrea columha in North-western Europe. 



2. List of the species of Ecliinoclermcita. — The following is the list 

 of the Echinodermata from Wady Mokatteb and Wady Badera. The 

 localities and zones of the accompanying fossils, where they are found 

 elsewhere, are also given : — 



* Quart. Journ. Geol. Soc. vol. xxii. p. 491, and note at the end of this 

 paper. 



f Quart, Journ. Geol. Soc. vol. xxi. p. 349. 



