BOTANY, CONCHOLOGY, AND GEOLOGY. 55 



rim of the glacier were copious ; and that forming 

 themselves into more or less parallel rills or streamlets 

 coursing to the south towards the sea, they scooped out 

 for themselves parallel channels which, continuing to 

 this day as depressions, are known by us as Madeque- 

 cham, Starbuck's, Coffin's, and Weir's Valleys, or fur- 

 nish long and comparatively narrow basins for the line 

 of ponds that stand all along the south shore of the isl- 

 and; these brackish-water lakelets being subsequently 

 kept in position by bars of beach sand, thrown up 

 along their southern ends by the sea. The present 

 writer does not know what is taking place with the 

 similar line of lakelets along the south shore of Mar- 

 tha's Vineyard; but it is very clear that owing to 

 deposits of sand, brought down by the rains from the 

 neighboring slight hills, and the washing in and blow- 

 ing over of beach sand from the south shore, the 

 linear lakelets along the southern side of Nantucket 

 are slowly growing shallower, narrower, shorter, and 

 in some cases — e. (/., the Mioxes — disappearing so 

 entirely that it is a little difficult even to find their 

 former location. Subsequently to the channelling of 

 these parallel grooves the continent sank, and the sea 

 came up and surrounded the island. And then it was 

 that the South Shore, Great Point, Coatue, Brant 

 Point, the neck that joins Wauwinet and Coskata, and 

 Smith's Point were slowly formed as the youngest 

 parts of Nantucket, and that possibly a portion of the 

 eastern end of the island along 'Sconset, Sancoty, and 

 Squam Banks was battered at by the mighty impact 

 of the storm billow and torn away. Thus probably 

 did the island take its present shape. 



