102 PEOCEEDIXGS OF THE GEOLOGICAL SOCIETY. [Jan. 24, 



below the surface of tlie Sahara to the same cause. As to the 

 existence of moraines, he was not surprised to find them in the 

 Atlas, as they were already knoAvn in the mountains of Granada. 

 As to the escarpments, it was now well known that, as a rule, they 

 assumed a direction approximately at right angles to the dip of the 

 strata ; and he felt inclined to consider that the bulk of the mounds 

 at the foot of the escarpment of the Atlas were rather the remains 

 of a long series of landslips from the face of the cliffs than due to an 

 accumulation of moraine matter. 



Mr. D. Forbes commented on the similai-ity of the rocks to those 

 of the Andes in South America. In the Andes the porphyritic tuffs 

 appeared to belong to the Oolitic age ; and the igneous rocks asso- 

 ciated with them were of the same date. He thought that, so far 

 as the author's observations had gone, the structure of the Atlas was 

 much the same as that of the Andes. 



Mr. W. W. Smyth mentioned that in the district to the east of the 

 Sierra Nevada, in the south part of Spain, where there was great 

 summer heat, and also heavy occasional rainfall, the same tufaceous 

 coating as that observed in Morocco was to be found. He had been 

 led to much the same conclusion as to its origin as that arrived at 

 by Mr. Maw. The upper part was frequently brecciated, and the 

 fragments recemented by carbonate of lime. 



Mr. Seeley, though accepting Mr. Etheridge's determination as 

 to the Cretaceous age of the fossils if found in England, could not 

 accept it as conclusive in the case of fossils from Morocco. The 

 genus Exogyra, for instance, which ranges through the secondary 

 and up to existing seas, might well belong to some other age; and even 

 the fossils presumably Miocene might, after all, date from some 

 other period. 



Mr. Maw, in reply, stated that he agreed with Mr. Ball as to the 

 rise in the Morocco plain as it approached the Atlas, and pointed 

 out that his section actually represented a rise of 400 feet from the 

 city of Morocco to the foot of the boulder mounds ; but in addition 

 to this gradual rise there was a range of altitude of 2000 feet from 

 the foot to the summit of the boulder beds. 



He also pointed out the resemblance between the interrupted oc- 

 currence of the boulder mounds in the Atlas and the distribution of 

 glacial moraines in the E-hone valley, and in the valley of the Esk, in 

 Forfarshire. As a proof that the boulder mounds on the flanks of the 

 Atlas consisted of transported blocks, he mentioned the fact that 

 the red sandstone rock of which they were composed did not occur 

 in the adjacent escarpments, and was not to be found within four or 

 five miles. There was, moreover, a mixture of different materials 

 in the mounds. 



Januaet 24, 1872. 



Henry Ludlam, Esq., of 174, Piccadilly, "W., and Charles White- 

 head, Esq., J. P., F.L.S., E.S.A., of Barming House, Maidstone, were 

 elected Fellows of the Society. 



The following communications Were read :— « 



