128 A OTT ORS 4 Aa Ss Mikel CHES: 
After the deposition of the fossiliferous sand and clay beds of the 
Scarboro’ Heights section, according to the view taken in this paper, 
an outflow east from the lake basin at Rome began. On account of 
the depression of the land, which brought on this final Champlain 
epoch of the Ice Age,.the relative height of the land in the vicinity of 
Toronto, as compared with the depressed region about 190 miles east- 
ward at Rome, then permitted a stream to erode its valley near Toronto 
to a depth below the present level of Lake Ontario. Later, and after 
a temporary advance and second retreat of the ice border at Scarboro’ 
and Toronto, forming a thick till deposit, the differential reélevation 
of the land, probably 200 to 300 feet more at Rome than in the west 
part of the Ontario basin, caused the water level of Lake Iroquois to 
rise gradually on the land westward until it stood at last permanently 
during many years at the conspicuously developed Iroquois beach. 
The uppermost till of the Scarboro’ Heights, that is, the second till 
deposit above the fossiliferous beds, seems to be a retreatal moraine, 
belonging to the second glacial recession, or to a third retreat after a 
second slight readvance, all considerably antedating the eee 
beach, which lies above all these drift accumulations. 
A Needed Term in Petrography. By . V. PiRsson. 
The term crystal carries with it an essential idea of outward geo- 
metric form produced by plane faces arranged according to certain laws 
of symmetry. The studies of crystals made in the recent past have 
added to this conception also the idea of a necessary interior molecular 
structure and certain definite physical properties. 
Thus, at.the present time, there is no definite term to designate the 
more or less rounded or formless masses in which minerals occur, 
especially in rocks which yet possess the interior molecular structure 
and physical properties of crystals. For such spheroidal or formless 
masses the term azhedron (without planes) is proposed, and such 
mineral masses may also be spoken of as possessing an anhedral 
¢ 
development. 
(Other abstracts deferred to next number.) 
