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out more sections to determine positively the prevailing strike of these beds. The incumbent drift is very variable in thickness, and large erratics, from twenty to thirty feet in diameter, are seen resting on quartzose sand. The author saw no grounds for concluding that any cretaceous strata occur any where in the island, nor could he find any fossils which appeared to have been washed out of a cretaceous formation into the tertiary strata, as some have suggested. 

My Lyell proceeds to the consideration of the organic remains collected by himself in Martha's Vineyard.

[[underlined]] Mammalia [[/underlined]].-- A tooth, identified by Prof. Owen as the canine tooth of a seal, of which the crown is fractured. It seems nearly allied to the modern [[underlined]] Cystophora proboscidea. [[/underlined]] 

2. A skull of a walrus, differing from the skulls of the existing species ([[underlined]] Trichecus rosmarus [[/underlined]], Linn.), with which it was compared by Prof. Owen, in having only six molars and two tusks, whereas those of the recent have four molars on each side, besides occasionally a rudimentary one. The front tusk is rounder than that of the recent walrus.