THE GEOLOGY OE GIBRALTAR. 515 



The shale and grit marked 1 resemble those that overlie the 

 limestone of Gibraltar, and after disturbance have been planed 

 across, apparently by marine denudation, before the deposition of the 

 strata marked 2, so that the same bed of grit occurs three times in 

 the section. The upper surface of the shale and grit is about 12 or 

 15 feet above high-water mark, and the whole length of the cliff is 

 about 35 feet. Beneath the point marked a our party, consisting of 

 Mr. Eoberts, several of the Sanitary Commissioners of Gibraltar, 

 and ourselves, were fortunate enough to discover a tooth and part of 

 the jaw of a fossil elephant, which, on comparison with specimens in 

 the Museum of Practical Geology, proved to be that of Elephas 

 antiquus. On showing it to Dr. Leith Adams, he identified it as a 

 right ultimate molar of the upper jaw (fig. 9). We believe it is the 

 first fossil tooth of an elephant that has been found in Africa ; and it 

 is specially interesting as being of a species which was the ancestor 

 and a mere specific variety of the living African elephant. It is 

 well known that Eleplias antiquus has also been found in a raised 

 beach at Gibraltar ; and in connexion with relative elevations and 

 depressions of land with regard to the sea-level and the ancient 

 union of Africa with Spain, this discovery is of some importance*. 



Superficial Deposits, &c, oe Gibraltar. 



The superficial formations of the Hock present certain features 

 which render them peculiarly interesting to the student of Pleisto- 

 cene geology. They comprise massive accumulations of limestone- 

 agglomerate, bone-breccias, deposits of calcareous sandstone, raised 

 beaches, and loose sands. These will be described, as near as may 

 be, in chronological order. 



1. Older Limestone-agglomerate of Buena Vista, Sfc. 



The oldest of all the superficial accumulations is the remarkable 

 agglomerate or breccia which covers so large an area in the district 

 of Buena Vista and Eosia and in the neighbourhood of the South 

 Barracks. Similar accumulations are met with in other parts of the 

 Rock ; but these, as we shall afterwards point out, belong to a later 

 date. In caves and fissures, as is well known, breccias also occur ; 

 but these are distinguished from the others by the presence of 

 abundant mammalian remains. They fall to be described, therefore, 

 under a separate heading. The breccia of which we are now about 

 to speak is quite unfossiliferous, and appears as a distinct superficial 

 accumulation, covering considerable areas, and resting sometimes 



* [An ultimate right upper molar, with the loss of a few anterior ridges and 

 holding fifteen plates and a posterior talon, is 8 by 3| inches. The enamel is 

 thick, and disks of wear well-shown, with central expansions, angulations, and 

 crimping of the enamel. There are eleven worn disks in a space of 6£ inches. 

 The crown resembles the variety of E. antiquus to which Falconer gave the 

 name E. prisms, and the disks and thick enamel are like the same parts in the 

 molar of E. africanus ; but the ridge-formula much exceeds that of the latter 

 species. It belongs to the thick-plated variety of E. antiquus referred to in my 

 monograph on Elephas antiquus, Palseontographical Society's Memoirs, 1877. 

 p. 31.— A.L.A.] 



