Woodworth.] 212 [Feb. 7, 
In tlie course of certain eskers, particularl3' wliere interrupted 
by a drunilin, I am informed by Mr. Barton, scour-ways or 
drainage creases are apt to occupy the interval. Such furrows 
are common in frontal moraines, where they are clearly not of 
superglacial origin but arise from the outflow of the subglacinl 
drainage, as on the islaml of Martha's Vineyard.^ Those 
creases arising in the interior of the ice-sheet are not so clearly 
i-eferable to subglacial streams, and they require further examina- 
tion. 
The following provisional table of effects due to glacial rivers 
assembles the phenomena known to me. 
Glacial Rivers are indicated 
within the ice-sheet, by 
forms due to erosion : 
pot-holes, 
scour-ways, or furrows, 
forms due to deposition : 
kames, 
eskers, 
pitted-plains, kame-fields. 
outside the ice-sheet, by 
forms due to erosion : 
drainage creases, 
forms due to deposition (partly in contact with ice) : 
terraces, lateral and frontal moraines ; hillside 
kames (Stone), 
snnd-plains, osar-plains (Stone), 
over-wash plains, aprons, 
valley trains (Salisbury). 
Relation of Eskers to Existing AVater Courses. 
Glacial and existing drainage lines usually exhibit discor<lance. 
Eskers commonly lie above the drainage line of meridional 
valleys, as below Woonsocket, R. I., near Ragge<l Mt., Conn. 
Existing streams frequently intersect eskers, by erosion, or by 
depression of the esker crest-line. The Bungay, Charles, and 
other rivers in Massachusetts cut across eskers. The trough or 
series of shallow kettle-holes marginal to an esker has sometimes 
become the course of a streafn, which then becomes construc- 
tional by glaciation, and may be called an eskerside stream. 
Exam]des occur on the Providence sheet. 
1 N. S. Shalcr: Srvciitli Amiiial rciu.rt [J. 8. ^p"'- ^'Tv. 
