140 M. de Buch on the 
the soil of all is more free of gravel and of better quality 
than that of the plains. Springs burst from the sides of 
some of them, and small lakes are found on the summits of 
some of the principal. In proceeding from Nisqually to Puy- 
allip, five terraces, running across the prairie in an easterly 
and westerly direction, are descended, and only one inclining 
in a contrary direction is to be met with.* The occurrence of 
terraces is observable in the prairies south of Nisqually, but 
isolated mounds are less frequent than hereabouts. 
NisQuaLuy, 2d December 1848. 
On the Limits of the Chalk-Formation. By M. DE BUCH. 
The low latitude to which the chalk strata have attained, 
when compared with the jurassic formations, and_ still 
more with the paleozoic rocks, has been considered by M. 
Boue, with much appearance of truth, as the most ancient 
action of climateric influence on the fauna of the ancient 
world. The most northern point of the world at which 
chalk has hitherto been found, is, according to M. Forch- 
hammer’s observations, the neighbourhood of Thistedt, in 
Jutland, that is to say, near the 57° north latitude, nearly on 
a line with Aberdeen, in Scotland, Calmar Mittan, Twer, and 
Casan. Chalk does not reach so high a latitude in England ;f 
the last point where it is observed is the southern side of Rath- 
lin Island, at the Giant’s Causeway, in the latitude of Ape- 
wiade, Bornholm, and Tilsit. Flamborough Head, at 54° north 
latitude, is its extreme limit in England. In Russia, its limits 
become lower towards the south. From Grondo, where the 
* Judging from a rough topographical sketch, M. Tolmie means one of the 
five terraces, not a sixth; but I am not sure. 
+ The occurrence in Buchan, in Aberdeenshire, of tracts of country with 
chalk flints containing the usual animal remains, may be held as an intimation 
of the probable existence there of portions of the chalk-formation in some of 
the hollows at present covered up by diluvium. Many years ago we examined 
Buchan. We trust that ere long the existence or non-existence of deposits of 
chalk will be determined. Mr William Ferguson, in his amusing published 
Notices on Buchan, says he had not met with chalk. 
