24G A. S. PACKARD, Jr., ON THE GLACIAL PHENOMENA 



Fusus (Sipho) tornatus Gould. Frequent and of large size. 



Spirorhis sp. 



Balanus crenatus Brug. Frequent. 



Balanus Hameri. Frequent. 



Hyas aranea (Linn.) The claws quite large, showing that they belonged to individuals 

 of maximum size, occurred rarely. 



Mallolus rillosus Cuvier. This was first detected by Mrs. F. Allen of Gardiner, and identi- 

 fied by Sir Charles Lyell. It is rarely found. Sir C. Lyell, in a letter to Mrs. Allen, ob- 

 served its occurrence at Saco, having been found by a person in that town. 



Rosmarus obcsus Illiger. In the cabinet of the late Mrs. F. Allen is a walrus' tusk which, I 

 am informed, was taken to London by Sir C. Lyell and identified by Professor Owen. 



Bos americanus Gmel. [Plate viii., fig. 18, a, b,] A third upper molar and first premolar tooth 

 are in the collection of Miss Allen of Gardiner, to whose kindness in loaning these unique 

 specimens I am greatly indebted. A second upper molar belongs to the museum of this 

 Society. They agree in all respects with those in a skeleton in the museum of this So- 

 ciety. 



From a deposit of arenaceous clay finely laminated, has been taken, at a height 

 of one hundred and ten feet above the sea, a finely preserved specimen of Asterias 

 vulgaris Stimps., which is in the museum of this Society. Near this locality Mya aretmria 

 and Leda truncata have been forwarded me by my friend Mr. George J. Varney of that city. 

 The drift deposits at Brunswick contrast most widely with the equivalent 

 beds which we have described as occurring in Southern Labrador. All the 

 three divisions of the drift here develop their characteristic features. Resting upon the 

 grooved and striated (N. W. and S. E.) gneiss rocks which underlie the town, we have a 

 thick bed of blue tenacious fossiliferous clay which inclines gently toward the south. Upon 

 this lies the brick-yard clay, or modified drift into which the lowest beds graduate, which 

 is always well marked, and forms a large proportion of the arable land of the town. It is 

 exposed for miles along the shores of Casco Bay, on the river, and artificially. It is from 

 this bed that most of the boulders are derived. Again, resting upon the boulder clay, and 

 filling up its irregularities, is a broad sheet of stratified sand which forms the arid plain 

 upon which the town is situated. It is four miles long and five wide, and slopes gently 

 toward the sea at the rate of about fifty feet in three miles. This sandy plain must for- 

 merly have been the bottom of a shallow estuary into which the Androscoggin emptied its 

 waters before the Terrace Epoch, while the immense bodies of water were draining off, 

 during the elevation of the coast. For it was after the deposition of this immense body of 

 sand, evidently the terminal moraine of a local glacier, which scooped out the river bed of 

 the Androscoggin, that the river was turned eastward in its course, and emptied its waters 

 into the Kennebec, after which these sands were reassorted into terraces. 



These terraces are six in number upon the south side of the river, while upon the oppo- 

 site, or Topsham side, there are but two straight parallel ones which run nearly east and 

 west, following the course of the river at this point. Upon the south, or Brunswick side, of 

 the river, the highest and earliest formed terrace is indistinctly marked, and turns south- 

 ward from the river at nearly right angles to its present bed. The remaining ones are 

 longer, more perfectly formed, and assume successively a direction more parallel with that 

 of the river, until the two lower and most recently formed terraces lie almost exactly par- 

 allel to the two opposite ones upon the northern side of the river. 



