172 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
(4) The coarser sediments of all the basins are somewhat feldspathic 
but in those of the Norfolk Basin this feature is most highly developed. 
(5) All the basins give some evidence of contemporaneous igneous 
action. These features are most strongly marked in the Boston Basin 
and least developed in the Norfolk Basin. 
(6) The conglomerates of all the basins bear evidence of contem- 
poraneous erosion. 
(7) Evidences of dynamic metamorphism occur in all the basins but 
the metamorphism has not been intense except locally. _ Its effects are 
most marked in portions of the Narragansett Basin. 
(8) The Narragansett Basin is further characterized by the occur- 
rence of coal beds, fossiliferous shales, and carbonaceous material in 
the finer sediments and by muscovite, muscovite granite pebbles, and 
pebbles of fossiliferous quartzite in the coarser sediments. 
(9) The distribution of the muscovitic material and of the fossil- 
iferous quartzite suggests transportation from both northerly and 
southerly sources, but not for any great distances. 
(10) The local nature of the other sedimentary materials is opposed 
to the idea of the importation of material from Great Belle Island or 
other northeasterly sources by glaciers. 
(11) The Harvard Conglomerate is unlike the other conglomerates 
in character, composition, and appearance. The quartzite pebbles 
contained in it may be of aeolian origin. It has suffered intense 
dynamic metamorphism. 
STRATIGRAPHY oF THE ROXBURY AND NEIGHBORING CONGLOM- 
ERATES. 
GENERAL STATEMENT.—Some field data bearing on the lithology 
of the sediments have already been given in, connection with the 
discussion of the hand specimens. In this chapter the intention is 
to set forth only those facts that have to do with the distribution, 
textural variation, and bedding of the rocks and with the relations 
of the series to the subjacent terrane. Structural data will be pre- 
sented in the following chapter in connection with the discussion of 
the work of others. 
Tur Roxpury SERIES.— Distribution:— Arkose. In the Boston 
Basin deposits of arkose occur at Medford, East Dedham, and along 
