SCIENTIFIC SURVEY. 349 



with occasional talcose variations. Last year a portion of this 

 mass of schists was donomiuated talcose ; but now, for weighty 

 reasons, we prefer the term micaceous. 



Putting together the various items of information within our 

 reach, we suppose this schistose formation extends from Long lake, 

 on the line between Canada and New Brunswick on the river St. 

 Francis, to Bellows' Falls in Vermont. We have ourselves traced 

 it continuously for at least 300 miles out of the 340 of its continu- 

 ance, and have the observations of Sir William E. Logan and his 

 assistants for the filling in of the gap of 40 miles between the 

 north-east corner of Vermont and the south-eastern portion of 

 Maine. The Canadian Survey have also traced this formation 250 

 miles further to the north-east, to Gaspe, on the gulf of the St. Law- 

 rence, so that we have a formation here 590 miles long, and that 

 known, not by theory, but by actual observation. We think, 

 however, that the disposition of that portion lying in Maine does 

 not confirm the suggestion that the fossiliferous upper Silurian 

 limestones and slates of Memphremagog lake are traceable contin- 

 uously to rocks of the same age upon lake Temiscouata. Such a 

 belt must cross a high range .of mountains transversly ; while the 

 close proximity of the micaceous schists of the vicinity of Con- 

 necticut river east of Memphremagog and at Megantic lake to the 

 Maine schists, must render certain the existence of one belt lying 

 to the eastward of the more southern limestones, and perhaps 

 separating them into two belts. Those on Temiscouata lake, how- 

 ever, are of the same age, and may be a repetition of the Mem- 

 phremagog basin upon the opposite side of a complex anticlinal 

 axis.* 



On the Woboostoock stream near its sources are four large 

 ponds, known as St. John ponds. We carried across from the 

 north-east branch of the north branch of the Penobscot river, so 

 as to strike the Woboostoock midway between the two most 

 northern of these ponds, in No. 5, R. 11. Descending the Wo- 

 boostoock stream, we find no ledges until we pass the hist St. John 

 pond, in No. 6, R. IT. Boulders of mica schist and quartz are 

 common on the sliores of the stream and the pond, except for two 



* Sir William suggests, after hearing our statement of the difficulty, that possibly 

 the Silurian limestones do not enter Maine at all, but that the Memphremagog or 

 Dudswell series are connected with the Temiscouata rocks north of the river St. 

 John; thus lying altogether in Canada. 



