34 Prof. J. W. Jtidd. Second Report on Specimens 



examined, and the minerals in them are found to be identical 

 in character with those in the deposits already described. Some 

 small pieces of pottery and bone were found at depths varying from 

 8 to 27 feet from the surface. 



In the alluvial mud, which prevails from the surface to the depth 

 of 20 feet, small tubular and knot-like bodies abound. These are 

 undoubtedly formed by the deposition of calcium carbonate on the 

 rootlets of plants, giving rise to beautiful calcareous tubes, and to 

 knot-like bodies where the rootlets branch. These calcareous tubes 

 and knot-like bodies are covered on the outside by cemented mud- 

 grains, and present a singular resemblance to some of the arenaceous 

 foraminifera like Astrorhiza. The knot-like bodies are evidently 

 formed where the rootlets have branched or become twisted, and 

 certain of them simulate in outward form some of the bodies referred 

 to as StacJieice. As we go downwards in the deposit, these bodies 

 become fewer in number and less definite in form ; and in the clay 

 from depths between 75 and 92 feet, we find no such tubular bodies, 

 but instead of them masses of concretionary limestone or "race," 

 probably resulting from the solution and re-deposition of the calcium 

 carbonate. The sand, which prevails from depths of 20 to 75 feet, 

 varies in coarseness, and is almost always well rounded and evidently 

 wind-borne, and is in places indurated into a sand-rock or imperfect 

 sandstone. 



From 75 feet to 92 feet an indurated alluvial mud was found. 

 The tube-like bodies are here wanting, bat in their place we find the 

 irregular masses of concretionary argillaceous limestone or "race," 

 evidently formed, as we have seen, by the solution and re-deposition 

 of the calcium carbonate originally deposited on the root-fibres. The 

 most careful washing of these clays by my assistant, Mr. F. Chap- 

 man, failed to reveal any trace of contemporary organisms, but at a 

 depth of 90 feet he obtained a good specimen of a Nummulite (N. 

 Gtiettardi, d'Arch. and Haime) evidently derived from the Eocene 

 limestones of the country. 



At the depth of 115 feet a very noteworthy change was found to 

 occur in the characters of the beds passed through, a mass of coarse 

 sand and shingle being met with, and this continued to the depth of 

 151 feet. At the latter depth a band of yellow clay 2 feet thick was 

 passed through, and under it sand and shingle beds prevailed till the 

 lowest depth reached, 345 feet. Specially coarse shingle beds were 

 found at depths of 121 feet, 160 feet, 175 feet, 190 feet, 208 feet, 

 250 feet, 265 feet, and 270 feet. In some of these shingle beds the 

 fragments, which were usually well rounded — often, indeed, perfect 

 pebbles — were very coarse, the fragments being of all sizes up to 

 that of a hen's egg. 



It is interesting to note that a boring made at Rosetta in the 



