SOME GLACIAL WASH-PLAINS. 103 



the pits on North avenue (now so-called Massachusetts 

 avenue), near the car stables, revealed frequent reversals 

 of cross-beddhig of the tidal sort, giving the impression 

 that the plain was formed l)cneath sea-level. The exten- 

 sion of the plain eastward into Carabridgeport favors the 

 same view, but no decisive facts have been gathered to 

 exclude the hypothesis of a glacial lake at the level of 

 about thirty feet above the present sea-level. In connec- 

 tion with this higher water level, it should be mentioned 

 that there is, in the outer margin of this phiin, a distinct 

 furrow or crease, occupied by Willis Court, which joins the 

 Charles River at Gerrv's Landing. This old drainajxe 

 furrow is now partly submerged by the Charles and occu- 

 pied by marsh deposits. 



Sporadic plains. — Between the lines of dominant sand- 

 plains and moraines outlined in this paper there occur 

 sporadic plains built without definite arrangement between 

 and around masses of melting ice. Until the actual ice- 

 contacts in this area are carefully i)lotted and the super- 

 position of wash deposits has l)een made out, further 

 mention of these deposits can bo of little more value than 

 to guide students to them. The following notes are re- 

 corded for the sake of those who desire to undertake the 

 study of promising localities. 



On the Taunton sheet the mass of gravels on the southern 

 border of Cedar Swamp should be examined. The course 

 of the Three Mile River from Norton reservoir southeast- 

 ward to Taunton appears to be determined by constructive 

 depressions between sand-plains. 



On the Abington sheet, the shores of the numerous 

 lakes and so-called ponds are invariably formed by wash- 

 plains. The course of the North River is through a re- 

 gion of plains and morainal mounds. Monponset Pond, 

 on the south, is one of the saddle-bag type, like Cunliffe 



