Geological Society. 233 



the pressure varies as the velocity created by it in a given time. 

 This great law of dynamics, therefore, is not fundamentally distinct 

 from the laws of aggregation, but follows from them with the addition 

 of a postulate more simple than itself. 



A proof was also given by Professor Stokes, of the theorem that 

 " Every Equation has a Root." 



May 2. — Professor Miller made a communication " On the em- 

 ployment of the Gnomonic Projection of the Sphere in Crystallo- 

 graphy." 



GEOLOGICAL SOCIETY. 

 [Continued from p. 155.] 

 June 22. 1859.— Sir C. Lyell, Vice-President, in the Chair. 

 The following communications were read : — 



1. " Further Observations on the Ossiferous Caves near Palermo." 

 By Dr. Falconer, F.R.8., V.P.G.S. 



Dr. Falconer, in the first place, adverted to his previous com- 

 munication, read on the 4th of May last, before his collections 

 had arrived in England. In the present paper he submitted, with 

 more detailed explanations, the materials on which his first state- 

 ments were founded. Dr. Falconer then described the physical 

 geography of that portion of the northern coast of Sicily in which 

 the ossiferous caves abound, namely between Termini on the east 

 and Trapani on the west. Along the Bay of Palermo, and again 

 at Carini, the hippurite-limestone presents inland vertical cliffs, from 

 the base of which stretch slightly inclined plains of pliocene depo- 

 sits, usually about \\ mile broad, towards the sea. The majority of 

 fossil shells in these tertiary beds belong to recent species. At the 

 base of those inland cliffs, but sometimes 50 feet above the level of 

 the plain, and upwards of 200 feet above the sea, the ossiferous 

 caves occur. One of the best known of these is the Grotto di 

 San Giro, in the Monte Griffone, aliout two miles from Palermo. 

 This cave has been often described. Like many others, it contains 

 a thick mass of bone-breccia on its floor, extending also beyond its 

 mouth and overlying the pliocene beds outside, where great blocks 

 of limestone are mixed with the superficial soil. The bones from 

 this cave had long been known, and were formerly thought to be 

 those of giants. Some years since, bones were here excavated for 

 exportation ; and M. Christol at Marseilles was surprised to re- 

 cognize the vast majority of remains of two species of Hippopotami 

 amongst bones brought there, and counted about 300 astragali. 

 Besides the Hippopotamus, remains of Elephas also occur. Prof. 

 Fcrrara suggested tliat the latter were due to Carthaginian ele- 

 phants, and the former to tlie animals imported by the Saracens for 

 sport. The Government of Palermo having ordered a correct 

 survey of this cave and its contents, it was found that beneath the 

 bone-breccia was a marine bed, with shells, and continuous with 

 the external tertiary deposits. The wall of the cave to the Iieight 



