MUSEUM OF COMPAUATIVE ZOOLOGY. 101 



dangerous to boats, our examinations were continued from Pemadumcook 

 Lake to the foot of the North Twin, whence, returning to Ambejijis 

 Lake, we proceeded up the Penobscot. 



For the first ten days our party consisted of six persons, two boats' 

 crews ; — one made up of my companion in two former trips to Ktaadn, 

 Dr. Crosby, of Waterville, Me., his son and nephew ; the other, of Mr. 

 L. E. Blake, of Worcester, Mr. Clapp, and myself. In sounding length- 

 wise of the lakes, our boats often took opposite sides, and, landing fre- 

 quently upon the shores and islands, we carefully viewed the unusually 

 wide extent of rocky siu'face laid bare through the long-continued 

 drought. Veiy nearly the same conditions observed in one were found 

 to prevail in all the other lakes and their connecting streams. All are 

 bordered by detrital deposits, constituting occasional sandy or pebbly 

 beaches of small extent, but ordinarily made up of granite bowlders 

 having angles but little rounded by attrition, and which are often so 

 crowded together as to resemble walls. The smaller islands that stud 

 the lakes are sometimes banked up on all sides, or wholly covered over, 

 with bowlders that have been borne to their present resting-places by 

 the action of ice in successive winters. 



The only occurrence of rock in place, upon any of the lakes and 

 throughfares visited, was observed later upon the Upper Joe MeiTy, 

 which lay to the west of our route from Schoodic Lake to the Middle 

 Joe Merry. On the return of Dr. Crosby and his companions, at the end 

 of ten days, they " carried" from the Middle to the Upper Joe Merry, 

 which has a length of about three miles. An examination of its mar- 

 gin, made at my request since I was myself to return from Ktaadn by 

 the Aroostook route, discovered upon a projecting point a granite ledge, 

 which for seventy-five feet forms the shore, rising steep ten feet from the 

 water. The southern half of the lake was ci-ossed, but, with the excep- 

 tion named, only shores of drift wei'e seen. Soundings were at the 

 same time taken, which will be given in the tables of depths. 



Ambejijis Lake, uppermost of the series of expansions of the Penob- 

 scot known as the Pemadumcook chain of lakes, and but two miles long 

 by three fourths of a mile wide, i-eceiving directly Avhatever of detritus 

 is swept down by the rapid river above, might be expected to be shal- 

 lower than the rest. It proved, however, to be deeper than the average 

 of the others, and here at one place was made the deepest sounding, 51.1 

 feet, that occurred in the series. This lake was once a connecting link 

 between Pemadumcook and the larger Millinoket Lake on the east, 

 which, according to Wells, has an area of eighteen square miles, while to 



