248 



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



S. E. and N. W. on each side of the hill, following the natural declivity of the rock. 

 They agree closely with those described at Gardiner and Augusta, with slight local varia- 

 tions j consisting, in the upper beds, on S. E. side of the hill on Canal Street, of more fre- 

 quent alternations of arenaceous beds. First, in ascending order, is a bed of 

 hard blue clay containing the numerous deep-sea forms enumerated below, 

 which have been found at this locality by Mr. C. B. Fuller, without whose kind 

 assistance this list could not have been prepared. These beds of pure clay 

 pass into beds containing patches of sand and grit, until at a level varying from 

 twenty-five to forty feet above the sea, following the slope of the surface, the beds 

 are composed of sand, with an almost entire absence of boulders, but contain- 

 ing a few angular pebbles of quartz. These sandy beds alternate with thin 

 beds of fine sandy mud, in which abound very perfect casts of Fury echinus dro- 

 bachiensis, numerous valves of Serripes, united valves of Mgtilus edults, and very 

 perfect casts of the holes of Mya armaria (see figure 4, near the top), showing that 

 the animal after death had been replaced by mud, which had been washed into 

 the empty shell, thus proving the tranquillity of the waters of that period. 



"We have never found living specimens of Mya armaria of such great size and 

 abundance growing with Scrripes gronlandicus, and in almost equal abundance, as 

 the latter is usually, in Labrador, only found in from ten to twenty fathoms. 

 Section of beds The presence of Euryechinus in abundance also shows that the sea could only 

 at Portland, i e. nave \ )eeQ f our or f lve fathoms deep, while the beds of clay lower down in these 

 series must have been deposited in a sea ten to twenty-five fathoms deep. 



This deposit is unconformably capped by xevy thick beds of coarse sand and shingly 

 gravel, precisely as at Gardiner, and about Boston. The lowest beds of tough blue clay 

 are of the same origin as at Mere Point, Brunswick, while the brickyard clays inland are on 

 the same horizon with the higher and more sandy beds. This point was more exposed to 

 oceanic currents and tidal action, as evidenced by the frequent alternations of sands and 

 sandy beds of clay, while the brickyard clays were deposited in estuaries and quiet pro- 

 tected bays. In these frequent alternations of beds of sand, which by their evenly bedded 

 strata indicate a period of great tranquillity of the sea, we see evidence of a continued, slow, 

 and almost imperceptible depression of the land during all this period. 



Euryechinus drbbachicnsis (Mull.) Found by Mr. E. S. Morse and myself very abundantly 

 and well preserved in nearly entire casts on Canal Street. 

 Eschara cleganhda D'Orb. Canal Street. 

 Stomatopora cxpansa Pack. On Buccinum undulatum. 

 Lepralla sp. 



Memlranipora amcricana D'Orb. This well-known form is not uncommon on shells. 

 Pccten gronlandicus Sowerby. Specimens from Mr. C. B. Fuller were thus identified by 

 Dr. Stimpson. (P. similis Laskey ? Fuller in the Report of the Maine Scientific Survey, 



1861.) 



In the usual abundance. From Mr. E. S. Morse. 

 Bost. Journ. Nat. Hist., iv. 1844. {N. infiuta Hancock. Ann. and 

 Common. 



Frequent. From Mr. Fuller. 

 Leda tcnuisulcata Couth. This I have received from Mr. Fuller. It is" a well-marked 

 specimen, agreeing precisely with the living forms, and is readily separated from any varie- 



Pccten islandicus Linn. 

 Nucida antiqua Mighls. 

 Mag. Nat. Hist, 1836.) 

 Leda buccata Steenstr. 



