Diluvial Deposits. — Recent Breccia. 27 



which the existing animals are so different from those of other 

 parts of the globe. It is remarkable, also, that no lime-stone 

 is among the specimens from the northern and western shores, 

 except that of the recent breccia ; and although negative con- 

 clusions are hazardous, it would seem probable, from this cir- 

 cumstance, that lime-stone cannot be very abundant or con- 

 spicuous at the places visited. — No eruptive mountains, nor 

 any traces of recent volcanic eruption, have yet been observed 

 in any part of Australia. 



V. The recent calcareous breccia, of which a description 

 will be found in the " Detailed list of specimens, " is one of 

 the most remarkable productions of New Holland. It was 

 found, during the expedition of Commodore Baudin, to exist 

 throughout a space of no less than twenty-five degrees of 

 latitude, and an equal extent of longitude, on the southern, 

 west, and north-west coasts*; and from Mr. Brown's speci- 

 mens it appears to occur also on the shores of the Gulf of 

 Carpentaria. The full account which M. Peron has given 

 of this formation, sufficiently shows its resemblance to the 

 very recent lime-stone, full of marine shells, which abounds 

 on the shores of the Mediterranean, the West India Islands, 

 and in several other parts of the world: And it is a point 

 of the greatest interest in geology, to determine, whether 

 any distinct line can really be drawn, between those con- 

 cretions, unquestionably of modern formation, which occur 

 immediately upon the shore : and other calcareous accumula- 

 tions, very nearly resembling them, if not identical, both in 

 the fossils they contain, and in the characters of the cementing 

 substances, that are found in several countries, at consider- 

 able heights above the sea. 



Dr. Buckland has described a breccia of modern formation, 

 which occurs upon the shore at Madagascar, and consists of a 

 firmly-compacted cream-coloured stone, composed of granular 

 fragments of shells, agglutinated by a calcareous cement f. 

 The stone of Guadaloupe, containing the human skeletons, is 

 likewise of the same nature ; and its very recent production 

 cannot be doubted, since it contains fragments of stone axes, 

 and of pottery \. — The cemented shells of Bermuda, described 

 by Captain Vetch §, which pass gradually into a compact lime- 

 stone, differ only in colour from the Guadaloupe stone ; and 

 agree with it, and with the calcareous breccia of Dirk Hartog's 

 Island, in the gradual melting down of the cement into the 

 included portions, which is one of the most remarkable features 



* Voyage, ii. p. 168, 169 — 216, &c. f Geol. Trans, vol. v. p. 479. 

 X Linnean Trans, xii. p. 53 — 57. § Geol. Trans. 2d Series, vol. i. 



p. 172. 



D 2 of 



