Vol. 55.] SOUTHERN MOEOCCO AND THE ATLAS MOUNTAINS. 213 



In consequence of the extreme difficulty attending exploration 

 in Morocco, any addition to our knowledge of the geology of the 

 Atlas range was of especial interest and reflected high honour 

 on the courageous explorer. The structure of the Moroccan Atlas 

 appeared to the speaker to he in harmony with that of Northern 

 Africa generally, where very ancient crystalline and metamorphic 

 rocks were immediately succeeded by Cretaceous strata. As the 

 Author observed, there was an entire absence of Palaeozoic rocks, 

 and we might add, of Triassic and Jurassic. Such was also the case 

 in the Nile Yalley and Arabia Petraea, with the exception, in the 

 latter country, of a slight representation of Lower Carboniferous 

 limestones (first recognized by Mr. H. Bauerman) at distant intervals. 

 The speaker considered that the Atlas range formed the margin 

 towards the north of the great Cretaceous basin which was spread 

 over the Desert of Sahara, and stretched across the Nile Yalley ; 

 and later, that of the Eocene Nummulitic sea. 

 Prof. Watts also spoke. 



