366 PROCEEDINGS OP IHE GEOLOGICAL SOCIETY, [Maxch 8, 



of introduced animals. The fossil remains of the " Genista" cave 

 establish beyond question that the rock was formerly either 

 peopled by, or the occasional resort of, large quadrupeds like the 

 elephant, rhinoceros, aurochs, deer, ibex, wild horse, boar, &c., 

 which were preyed upon by hyenas, leopards, African Ij^nx, and serval : 

 that the remains were transported by any violent diluvial agency 

 from a distance is opposed to all the evidence of the case. The 

 manner in which they were introduced into the Windmill Hill cave 

 we believe to have been thus : — The surface of the rock and its level 

 in relation to the sea were formerly different from what we now see. 

 The wild animals above enumerated, during a long series of ages, 

 lived and died upon the rock. Their bones lay scattered about the 

 surface, and in the vast majority of instances crumbled into dust, 

 and disappeared under the influence of exposure to the sun and other 

 atmospheric agencies, as constantly happens under similar circum- 

 stances at the present day. But a certain proportion of them were 

 strewed in hollows along the Unes of natural drainage when heavy 

 rains fell ; the latter, for the time converted into torrents, swept the 

 bones, with mud, shells, and other surface-materials, into the fissures 

 that intercepted their course; there the extraneous objects were 

 arrested by the irregularities of the passages, and subsequently soli- 

 dified into a conglomerate mass by long- continued calcareous infil- 

 tration. That elephants frequented the rock is proved by a valuable 

 specimen of the molar tooth of an extinct species, which we have 

 ascertained to be Elephas antiqims, discovered by Mr. Smith, of 

 Jordan Hill, in a sea-beach on Europa Point. That the hyenas 

 were dwellers upon the rock is also estabhshed by the fact that, in 

 addition to numerous bones, we have discovered a considerable quan- 

 tity of coprolites of Hycena hrunnea among the " Genista " cave 

 relics. Some of the species must have peopled the rock in vast 

 numbers. We infer, upon a rough estimate, -that we have passed 

 through our hands bones derived from at least two or three hundred 

 individuals of ibex swept into the Windmill Hill fissure ; in no 

 instance have we observed fossil bones attributable to one complete 

 skeleton of any one of the larger mammalia. 



That the rock now so denuded of arboreal vegetation was then 

 partially clothed with trees and shrubs, as the corresponding lime- 

 stone mountains on the opposite side of the straits are at present, is 

 so legitimate an inference as hardly to be open to rational doubt. 

 It is now a pinch to find sufficient food at the end of the hot season 

 for the flocks of goats which are reared on the promontory ; while 

 it is a matter of absolute difficulty to find fodder at all for the few 

 cows that are kept by some of the officers of the garrison. When 

 elephants, rhinoceros, wild oxen, horse, boar, deer, &c., &c. either 

 peopled or resorted to the rock in considerable numbers there must 

 have been abundant trees and more or less constant green food for 

 them. Bare exposed masses of rock get intensely heated by a 

 southern sun, they repel moisture by being thus heated, and raise 

 the mean temperature of the locality by radiation ; while, on the 

 contrary, a clothing of trees and of fruticose vegetation both 



