474 Mr. Horner on the Geology of the Environs of Bonn. 



" preserved specimen nevertheless appear to be Planorbis carinatus ; the rest 

 '' seem to belong to the same species." 



VI. Page 452. 



I visited the lignite deposit at Friesdorf in September 1835, in company 

 with Mr. Robert Brown, when he collected several specimens of the vegetable 

 remains. He informs me that all the wood he found is coniferous, which, 

 taken along with the evidence derived from the leaves already noticed, might 

 point rather to a temperate than an equinoctial climate. 



VH. Page 453. 



M. Agassiz examined the specimens accompanying this paper, in a late 

 visit to England. Besides the Leuciscus Papyraceus, he found another spe- 

 cies, which he named Leuciscus Macrurus. 



VHI. Page 462. 



Since this paper was read, I. have seen the loess in three situations, which 

 are remarkable as connected with the geological events which, in compara- 

 tively recent times, have occurred in this district. 



I learned in the summer of 1833, that, in the preceding spring, the pro- 

 prietor of the farm in the bottom of the crater of the Roderberg, in sinking a 

 well near his house, had passed through a bed of loess. I went there, accom- 

 panied by Mr. Lyell, and we ascertained that, after a few feet of scoriae, they 

 had found loess, and had penetrated it to the depth of 62 Rheinland feet 

 (63*2 English feet), but without passing through it. Part of that which had 

 been dug out was on the ground near the well, the rest had been scattered 

 over the adjoining field. It had the usual characters, and several of the cal- 

 careous stony concretions were lying about. 



In the left bank of the Rhine, a short distance below Neuwied, and near 

 Andernach, I observed the loess lying under a bed of volcanic scoriae, and that 

 covered by a considerable thickness of alluvial soil. 



On a visit to the Laacher See in September 1835, I observed a section close 

 by the edge of the lake, and within a quarter of a mile of the monastery, 

 where loess, containing its characteristic shells, is covered by a succession of 

 beds ol volcanic sand, scoriae, and pumice, and altered fragments of grau- 

 wacke. 



In a paper on the solid contents of the Water of the Rhine, which was read 

 before the Geological Society in March 1834, and published in the London and 

 Edinburgh Philosophical Journal for January 1835, p. 102, 1 showed that the 



