66 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
of the conglomerate. If melaphyr were associated with these beds, it 
also might remain unrevealed. Even if this be true, however, the occur- 
rence of melaphyr in association with beds higher in the series remains 
unaccounted for. 
It appears, therefore, that neither under the former interpretation nor 
under that which is offered here, is the melaphyr always associated with 
the basal beds of the conglomerate, or, indeed, with any definite horizon. 
On any interpretation, the occurrence of the melaphyr in association with 
sediments of all kinds, from the coarse conglomerate of Brookline to the 
slate of Allston, is suggestive of a considerable vertical distribution. 
EVIDENCE FROM StrRucTURAL Deraits. — There are some details of 
structure which have a bearing on the general question. At various 
points about the periphery of the Brookline area, small, isolated ex- 
posures of melaphyr are seen in contact with conglomerate. These do 
not differ, lithologically, from the larger mass. It is reasonable to sup- 
pose that they are connected with it. As the conglomerate dips away, 
in all directions, from the central area, it is clear that the melaphyr in 
these exposures is associated with sediments higher in the series than 
those which surround the main mass. In all cases the smaller masses 
are intrusive into the sediments. This suggests that the main mass also 
is intrusive. 
The conglomerate on the north bank of the reservoir, at Newton 
Upper Falls, dips away from the melaphyr on the south bank. The 
rock walls are but a few feet apart. It is evident that the dip of the 
conglomerate is not sufficient to carry the lower beds exposed above 
the melaphyr cliff. The strike of the conglomerate varies by about 12° 
from the trend of the parting between the two rocks, carrying it obliquely 
toward the melaphyr. Conglomerate, outcropping near Eliot Station, on 
the Boston and Albany Railroad, strikes toward melaphyr on the oppo- 
site side of the tracks (Plate 2, Loc. 8). On Walnut Street, Newton 
Centre, conglomerate, on the east side of the street, strikes directly into 
brecciated melaphyr on the west. On the corner of Commonwealth Ave- 
nue and Valentine Street is a small exposure of conglomerate which strikes 
toward the melaphyr mass. In the grounds of the Golf Club, on Centre 
Street, slate strikes directly across the trend of the melaphyr. On 
Foster Street, Brighton, sandstones, on opposite sides of the melaphyr 
mass, strike toward each other. These occurrences indicate deformation 
in the sediments preceding or contemporaneous with the intrusion of the 
igneous rock. 
On the east side of Chestnut Hill Avenue, Brighton, the conglomerate 
