MUSEUM OF COMPARATIVE ZOOLOGY. 95 
North American coast was also not far from its present altitude. These 
fragments lie at the height of about 150 feet above tide-water ; the most 
elevated point at which I have traced the Tertiary deposits of the Gay 
Head series is about the same height. Taken together, these two sec- 
tions afford interesting evidence of the existence of the shore line close 
to the present coast in two remote stages of the earth’s history. 
The occurrence of Cretaceous deposits in this part of New England is 
particularly interesting, for the reason that it indicates the former exten- 
sion of the deposits of this age to points much farther north than they 
have hitherto recognized on the eastern versant of the continent. Hith- 
erto, no beds of Cretaceous age have been known on the Atlantic coast 
north or east of New Jersey. This new locality establishes the existence 
of such beds about 100 miles farther north, and about 200 farther east 
than those which occur in the New Jersey area. 
The fact that the Martha’s Vineyard Cretaceous material was appar- 
ently deposited near a shore line, appears to indicate that the Cretaceous 
section, at least that part which belongs in this particular horizon, never 
covered the general surface of New England. Therefore we cannot 
fairly attribute to erosion the absence of this portion of the Mesozoic 
deposits in the New England area and the region to the northward. It 
seems to me more likely that these beds were never deposited on that 
portion of the continental surface. 
Palesontology of the Martha’s Vineyard Cretaceous. 
Although there can be hardly any question as to the general geologi- 
cal position of the beds whence these fossils were derived, their precise 
place in the section is not readily determinable with the material at 
hand. As will be seen from the appended figures of fossils, the remains 
are very imperfectly preserved, revealing the existence of four species 
which are characteristically Cretaceous in their aspect. The species, 
however, differs so far from that which has been found in more southern 
portions of the continent that no sufficient identification of the particular 
horizon is possible. 
The most abundant fossil is the Exogyra, shown in Figs. 19 and 20 of 
Plate Il. The specific differences between the several species of Exo- 
gyra are rarely if ever sharply defined. The Martha’s Vineyard form 
appears to be sufficiently distinct from any others which have been de- 
scribed to warrant the application of a new specific name. So far, no 
distinct. Exogyras have been found above the horizon of the Cretaceous 
