276 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
and one or two measured approximately by reference to bench-marks 
of the Metropolitan Water Board along the line of the Cochituate 
Aqueduct. 
Big sand plain at Needham (Boston map, contours). . about 160’ 
Sand plains 1 mile N. W. of Needham “ 43 160! 
Sand plain at S. end of Waban Lake (Met. W. B. b. wm) “ 150’ 
Sand plain just E. of Newton Up. Falls “ “ “ 150" 
Sand plain north of Wellesley Hills sta. (B. map) “ 150' 
Small sand plain cut by R. R., E. of Waban (hand-level) ‘* 154’ 
Big sand plain extending from Newton Centre through Re, 
Eliot to Waban (lobes 500’ W. of Chestnut St. bridge 
BIS): ines @) 14S" 
Sand plain near Woodall aa hesiant Sts. w alae Pr ern EST 
Waban sand plain, E. of Newton Lower Falls (Metrop. hoa 
Park. Com3)) son 2) ee . + « about 150’ 
(Hand-level altitudes underlined.) 
North of this line of plains, in general north of the Boston and Albany 
Circuit Railroad, there is a slight drop in the water-plane; for the well- 
known Newtonville plain has lobes at about 140 feet (by contours on 
the Boston map), and the little sand plain just northeast of Woodland 
station, which merges into the higher Waban plain, has lobes east of 
Washington Street at about the same height, as shown by the 140-foot 
contour. In general, however, all the plains in this part of the basin of 
the Charles, south of the Boston and Albany main line, are not far from 
150 feet in altitude. 
Near the Boston and Albany main line in Auburndale, West Newton, 
Newtonville, Newton, and Brighton, there is a very pronounced drop in 
the water-plane, marked by sand plains which lie about 80 feet lower 
than those just described, viz., at about 60 feet above sea-level. Most 
of these plains are rather obscured by settlement, e.g. those of Newton- 
ville, Waltham, and Waverley. 
There appear to be still lower plains near the Charles River, from the 
last-mentioned group northward, including one at Nonantum and one 
south of Commonwealth Avenue near Cottage Farm. The gravel plains 
of Cambridge and Arlington lie hardly more than 25 feet above sea-level. 
This rather sudden drop from the 160-140-foot plains to those of 60 
feet and under marks the change from Lake Charles into what Crosby 
has called Lake Shawmut (130), the smaller successor to Lake Charles, 
lying wholly within the Boston Basin. 
