2 it Geological Society. 



channel by which sea-water had been admitted. The waters of 

 the hot spring thus confined converted the area of the temple into 

 a lake, from which an incrustation of carbonate of lime was depo- 

 sited on the columns and walls. 



The proofs are, that the lower boundary of this incrustation is ir- 

 regular ; whilst the upper is a line of water-level, and that there are 

 many such lines at different heights ; — that salt water has not been 

 found to produce a similar incrustation ; — that the water of the 

 Piscina Mirabile, which is distant from the sea, but in this imme- 

 diate neighbourhood, produces, according to an examination by 

 Mr. Faraday, a deposit almost precisely similar; — that no remains 

 of Serpulse, or other marine animals, are found adhering to it. 



4% The temple continuing to subside, its area was again par- 

 tially filled with solid materials ; and at this period it appears to 

 have been subjected to a violent incursion of the sea. The hot- 

 water lake was filled up, and a new bottom produced, entirely co- 

 vering the former bottom, and concealing also the incrustation of 

 carbonate of lime. 



The proofs are, that the remaining walls of the temple are 

 highest on the inland side, and decrease in height towards the sea 

 side, where they are lowest ; — that the lower boundary of the space 

 perforated by the marine Lithophagi is, on different columns, at dif- 

 ferent distances beneath the uppermost or water-level line; — that 

 several fragments of columns are perforated at the ends. 



5. The land continuing to subside, the accumulations at the 

 bottom of the temple were submerged, and Modioli attaching 

 themselves to the columns and fragments of marble, pierced them 

 in all directions. The subsidence continued until the pavement of 

 the temple was at least nineteen feet below the level of the sea. 



The proofs are derived from the condition of the columns and 

 fragments. 



6. The ground on which the temple stood appears now to have 

 been stationary for some time, but it then began to rise. A fresh 

 deposition, of tufa or of sand, was lodged, for the third time, within 

 its area, — leaving only the upper part of three large columns visible 

 above it. 



Whether this took place before or subsequently to the rise of 

 the temple to its present level, does not appear; but the pave- 

 ment of the area is at present level with the waters of the Mediter- 

 ranean. 



The author then states several facts, which prove that consi- 

 derable alterations in the relative level of the land and sea have 

 taken place in the immediate vicinity. An ancient sea-beach ex- 

 ists near Monte Nuovo, two feet above the present beach of the 

 Mediterranean ; — the broken columns* of the Temples of the Nymphs 

 and of Neptune, remain at present standing in the sea ; — a line of 

 perforations of Modiolae, and other indications of a water-level 4< 

 feet above the present sea, is observable on the sixth pier of the 

 bridge of Caligula ; and again on the twelfth pier, at the height of 



