Geological Society of London. 29 



Mr. Gwjm Jeffreys also considered that every palaeontologist 

 ought to be a naturalist, as the fossil and recent forms are inti- 

 mately connected by insensible gradations. All the Echinocardia 

 with which he was acquainted were inhabitants of clean sand. 



Dr. Duncan, in reply, stated that if the Spatangidas were clas- 

 sified, generic distinctions would be observed quite irrespective of 

 the presence of fascicles. He considered the fascioles, like the horns 

 of Mammalia, of third-rate structural importance. One specimen 

 from Arabia appeared to have a fascicle developing. He remarked 

 that all the fossils were of the same size, so that it was impossible 

 to determine whether the formation of fascioles was dependent on 

 embryonic conditions, or whether they were developed in the perfect 

 animal. 



II. December 9th, 1868. — 1. "Notes of a Geological Keconnais- 

 sance in Arabia Petr^a." By H. Bauerman, Esq., F.G.S. 



The district to which this paper referred is that between Suez and 

 the lower part of "Wady Ferran, in the Peninsula of Arabia Petra^a, 

 and includes the copper and turquoise mines worked by the ancient 

 Egyptians. The rocks within this area were classified as follows : 



1. Gneiss and granites, forming the central chain of Sinai and the hase 



of all the stratified deposits. 



2. Eed Sandstone series. 



3. Cretaceous rocks. 



4. "White limestones, with flints, salt, and bitumen. Eocene. 



5. Flint conglomerate, with coralline limestone. Miocene. 



6. Gypseous marls of "Wady Taragi. 



7. Keconstructed gypseous sands and conglomerates. 



8. Eaised beeches, coralline and miliolitic limestones. 



9. Alluvium and desert drift. 



The Eed Sandstone series consists of three members, a thin bed of 

 limestone being the central, and containing remains of encrinites, 

 referred by Mr. Etheridge to the Muschelkalk form Encrinites moni- 

 liformis. Iron, manganese, and copper ores are found near Nasb 

 and Serabib el Khadem. The turquoise mines of Wady Maghara, 

 which were referred to the same horizon, are among the most ancient 

 monuments of the world. The author considered that the tools 

 employed were flint chisels or flakes, and hammers made from pieces 

 of a neighbouring doleritic lava. The flakes were supposed to have 

 been mounted on wooden blocks. 



The Cretaceous rocks which rest unconformably on the Triassic 

 sandstones, consist chiefly of green sand, with alternations of thin 

 argillaceous limestones, containing Echinoderms, which prove them 

 to be of the age of the Upper Greensand. Above them comes the 

 Hippurite-limestone series. The fossils were described by Dr. 

 Duncan, F.E.S., in a subsequent communication. 



The white limestone, with flints, the next group of rocks in 

 ascending order, strongly resembles the European Chalk with flints ; 

 but, according to the author, it must be regarded as representing the 

 Nummulitic limestone of Egypt, as several species of Nummulites 

 have been detected in it near the shores of the Eed Sea, below Wady 

 Gharandel. The Miocene flint conglomerate series is a mass of coarse 



