Geological Society. 291 



PROCEEDINGS OF LEARNED SOCIETIES. 



GEOLOGICAL SOCIETY. 



March Sth. UUl.— Prof. W. W. Watts, Sc.D., M.Sc, F.R.S., 

 President, in the Chair. 



The following commum cation was read: — 



' Contributions to the Geolog_v of Cyrenaica.' 

 liy Prof, J. W. Gregory and others. 



(ii) Notes on the Kainozoic Mollusca. By Richard BuUen 

 Newton, F.G.S. 



Tlio Author determines a number of mollusca which are recog- 

 nized as belonging to various members of the Kainozoic System, 

 namely, post-Pliocene, Holvetian-Tortonian or Vindobonian, Aqui- 

 tanian, Priaboiiian, and Lutetian. The most abundant of the post- 

 Pliocene series is Oerastoderma edide, a species largely distributed 

 over Northern Africa and the Mediterranean countries generally. 

 Among the Helvetian-Tortonian forms are Alectrijon'm cf. virleti and 

 Stromhus cf. coronatus — well known in North African rocks of 

 this age, as well as in those of other Mediterranean regions. 



The Aquitanian shells present a relationship to the ' Schio- 

 schichten' fauna of Northern Italy, and consist mainly of Pectinoid 

 species, such as Pecten vezzanensis, JE'iuipecten cf. I'xisinii, and 

 Spondijlus cisalpinus, etc., associated Avith ^quipecten zitteli, 

 ^E'/. carnaretensis, and JEq. scabrellus, which are indicative of the 

 later age — Burdigalian or Helvetian. This admixture of species, 

 according to Dr. Oppenheim's memoir on the ' Schioschichten,' is 

 also known in the fauna of those rocks. Foraminiferal organisms 

 {Opercidina,Qtc.) occur in these beds, but no nummulites. Lejpido- 

 cifclina elephantina, a good Aquitanian species, is found with 

 Oojjecten rotundatus from Birlibah. 



The most characteristic of the Priabonian mollusca is Pectea 

 (ux'uatics, a species occurring in Northern Italy, the Balearic Islands, 

 AJgeria, Tunis, the Balkan Peninsula, Armenia, etc. A new 

 species of ^qidjyecten is described. Nummulites abound in these 

 rocks. 



An indeterminable ostreiform shell has been collected in the 

 neighbourhood of Ain Sciahat, associated with the large Nummulites 

 gizehensis — thus demonstrating that Lutetian rocks are present in 

 Cyrenaica. So far as the mollusca are concerned, nothing older 

 than Lutetian has been observed in this collection. 



