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latter. They are briefly these : 1st, from the evidence of the 

 existence of birds during their deposition ; in no other portions 

 of the new red Sandstone are there similar impressions of bird 

 feet, and the existence of birds on the earth during the Triasic 

 period is wholly unsustained by any other geological evidence ; 

 2nd, from the occurrence of the bones of large vertebrata ; 

 3d, from the occurrence of remains resembling those of the 

 Oolite, and from the abundance of fossils, which is not charac- 

 teristic of the new red Sandstones of this country. The charac- 

 ter of the fishes has been considered a strong argument in favor 

 of these Sandstones belonging to a period anterior to the Lias ; it 

 has been assumed that they possess all the characteristics of the 

 older types, that they have heterocercal tails and rhombic scales. 

 But this is not the case, for the fishes of the Connecticut Sand- 

 stones, all coming from the upper beds, hold an intermediate 

 position between those with heterocercal and those with homo- 

 cereal tails, and may be referred with equal propriety to the 

 Lias Sandstones and to the Triasic period. If we still conclude 

 to refer these upper beds to the new red Sandstone, it must be 

 admitted that we have for the first time a division marked out in 

 these rocks, which may correspond with the divisions recognized 

 in the same formation in Europe. 



Prof. Agassiz alluded to a section at Nahant, where, under 

 masses of Sienite, may be seen a regular series of strata, con- 

 taining large quantities of fossil coraJs in an imperfect condition ; 

 he thinks these may prove a continuation of the Mansfield coal 

 formation. Perhaps the whole matter will be explained by the 

 strata in question proving to be metamorphic rocks. 



Mr. Desor remarked, that such different inclinations in Sand- 

 stone strata do not prove a difference of formation. At the 

 " Pictured rocks," strata are found with an inclination of 36° to 

 40°, while the next are horizontal, in some cases for a quarter 

 of a mile ; it is the same as what is seen in the tertiary deposits, 

 and called by Mr. Lyell " cross formation." 



Dr. Buckminster Brown presented, in the name of Mrs. 

 H. G. Otis, a specimen of the Caterpillar fungus, or vege- 

 table caterpillar, Spheria Robertsii. This rare insect was 

 brought from New Zealand. 



