No. 5. — On the Occurrence of Fossils of the Cretaceous Age on the 
Island of Martha’s Vineyard, Mass. By N. S. SHALER. 
Ir has long been known that fossils apparently of Tertiary age occur 
in the peculiar rocks about Gay Head, on the western extremity of Mar- 
tha’s Vineyard. These strata of alternating clays, sands, and occasional 
lignites occupy the western half of Martha’s Vineyard, in which region 
they rise above the sea level. They probably underlie the glacial de- 
posits throughout much of the area of the island, and may have a yet 
wider extension. Even where the Tertiary beds lie above the sea level, 
they are generally covered by a thick coating of glacial débris. Where 
this débris has the character of true shoved moraine, the accumulations 
are often a hundred feet or more in depth. Where the detritus exists 
in the form of a sheet, it is less continuous, but nevertheless covers the 
greater part of the underlying rocks, which are only exhibited in a clear 
manner along the gulf-like shores. 
In 1870, while engaged in some studies on the erosion of the coast 
lines of this island, I found several fragments of a coarse sandstone at va- 
rious points in the drift material, which contained extremely obscure mol- 
luscan fossils. Among these were specimens of what appeared to me to 
be Exogyra, a genus which, as is well known, does not extend to the Ter- 
tiary period, and is practically limited to the lower portion of the Creta- 
ceous. Although the evidence was extremely imperfect, it was enough 
to warrant a careful search of the island, with the hope of finding in 
place the beds whence the fragments were derived. I spent more than 
a month in this systematic inquiry before attaining to any results what- 
ever. At length I discovered two localities where these sandstone frag- 
ments with imperfect molluscan remains wére tolerably plenty. These 
positions are indicated in the descriptive sketch, Plate I. One of them 
lies on the western shore of what is called Lagoon Pond, immediately 
west of Cottage City. At this point a skilled collector may in the 
course of half a day discover half a dozen fragments scattered in the 
drift, which are clearly referable to Cretaceous rocks. A second and 
more important locality lies near the centre of the northern shore, at 
the distance of about three fourths of a mile from the coast line on the 
VOL. XVI. —NO. 5. 
