182 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
but is probably a case of overlap (k, p. 77). The relations of the 
conglomerate to the granite at this point are shown in Figure 5. Simi- 
lar phenomena at Hingham are described by Crosby. ‘The contact 
area lies in a field south of Hockley Lane, bounded on the north by 
melaphyr and on the east and south by granite. The relations of the 
conglomerate and granite are very intimate. The conglomerate is 
made up largely of angular and half-rounded debris of the same coarse 
red granite and of fragments which range from single grains of quartz 
and feldspar to masses two feet or more in diameter, sometimes only 
imperfectly separated from the parent ledge, the finer sediment appear- 
ing to penetrate the cracks in the granite (l, p. 215). 
In none of the cases mentioned is there an appearance of anything 
like boulder-clay at the contact with the underlying rock. The under- 
lying surface does not seem to have been smoothed, polished, nor 
striated. ‘These features, so common in our glaciated regions of the 
present day, are entirely absent. Instead the underlying surface 
bears evidence of deep disintegration under atmospheric agencies and 
of rearrangement and deposition of the loosened material in close 
proximity to its parent ledges. 
Summary of the Roxbury Series. (1) Arkose occurs in several local- 
ities along the border. 
(2) Conglomerate occurs in three broad, nearly east-west areas 
separated by bands of slate. The conglomerate areas narrow east- 
ward and disappear, while the slate areas broaden and appear to merge 
in the same direction. 
(3) Melaphyr occurs in several isolated areas as contemporaneous. 
intrusions or flows. 
(4) The coarse conglomerate occupies an axial position in the great 
conglomerate areas but varies greatly in texture in neighboring out- 
crops. ‘The rock becomes finer from west to east and from north or 
south toward the slate areas; but the decrease in coarseness consists 
rather in a change of the relative proportions of gritty or sandy material 
in the rock than in a difference in size of the pebbles; large pebbles 
occur in rocks that are chiefly grit. 
(5) Bedding is best developed toward the borders of the conglom- 
erate areas. Banding is the prevalent type, the frequency of occur- 
rence increasing as the slate areas are approached. 
(6) Lenses and streaks are of relatively infrequent occurrence. 
The former tend to appear as separated individuals in the same hori-- 
zon or in parallel horizons rather than in linear bundles or imbricated 
masses. 
