86 J. D. Dana on the origin of some of the 



torn would give the depth of the original excavation ; that of the 

 beds of sand over it, the thickness of the drift derived from the gla- 

 cier ; that of any clay hed, or infusorial bed, or shell deposits, and of 

 the peat, other important points in its history. The de]3th of the 

 basin was small compared with that of the Quinnipiac harbor, as is 

 evident from the present level of its meadows. 



4. Denudation. — In this era of submergence, the sea breaking 

 against the foot of East Rock and the other cliffs of the bay, must 

 have worn away the sandstone along the base, and thus carried for- 

 ward the degradation of the trap dikes and sandstone hills which had 

 been begun by the glaciers. The waves acted upon the region in front 

 of Pine Rock both from the direction of the Beaver Pond basin, and 

 that of the broad West River channel. The part of the Beaver Hills 

 occupying this position being thus attacked on both sides woidd have 

 been soon swept away and a free passage made across for the 

 waters. This spot is now occupied by a portion of the New Haven 

 plain, directly proving that waters communicated across from the 

 Beaver Pond basin to the West River channel, or the reverse, as just 

 stated; and the degraded condition of the front of Pine Rock is 

 further proof of the action of the sea here supposed. The sweep of 

 the tides across this region, would have some where made a tidal chan- 

 nel ; and this channel, as the high terraces either side show, was that 

 which after a while became, and now is, the outlet to the Beaver Pond, 

 along the north side of the Beaver Hills (see map). In like manner, 

 a depression was made in front of the larger part of Mill Rock, by 

 encroachments upon Sachem's ridge. The disjunction was not so com- 

 plete as in the case of the Beaver Hills, because the central basin of 

 the bay, the Beaver Pond, gave no aid through its currents and wa^'es, 

 since it was remote from Sachem's ridge, while close along side of the 

 Beaver Hills. As already observed, the streamlets descending the 

 front of the Rocks after rains would have aided in the process of denu- 

 dation, and with much gi'eater effect after the elevation of the land 

 which closed the Charaplain era. 



3. Life of the Champlain Era. 



More than a score of years since, according to Mr. I. Lorenzo Stiles, 

 the antlers of a buck were dug up at a dejjth of 10 or 15 feet at the 

 Stiles clay-bed near North Haven village. Mr. Stiles informs us that 

 they were those of the common species of deer. The specimen was 

 deposited in the New Haven Museum, an institution which years 

 since came to its end, and it has been lost sight of, so that the fact 



