127 
[Upham. 
The hind foot of Otozoum parvum is 5 inches long besides 
inches of heel. None of the specimens yet obtained show two 
tracks in succession. Otozoum caudatum was recognized twenty 
years ago in the Museum of Wesleyan University, the slab coming 
from Portland, Conn. It differs from the 0. Moodii chiefly in the 
forward direction of the thumb. The marks of a tail do not nec- 
essarily indicate its presence in one species and absence in the 
other. «• 
Illustrations of new varieties of the lower arthropods, worms and 
mollusca, will not be brought forward at this time, since our com- 
parative studies of the tracks of living animals related to them are 
not yet completed. 
MARINE SHELLS AND FRAGMENTS OF SHELLS IN 
THE TILL NEAR BOSTON. 
BY WARREN UPHAM. 
The fossils here described, occurring in drift deposits near Bos- 
ton, and belonging wholly to species that are still living in Massa- 
chusetts bay, have been previously noticed by several observers, 
who have regarded them as evidence of a marine submergence within 
ihe Pleistocene or Quaternary period. Instead of this, my obser- 
vations made during the past summer and autumn show that these 
fossils were transported from the bed of the sea on the north by the 
ice-sheet in the same manner as the materials of the drift, includ- 
ing its boulders and rock fragments, large and small, have been 
carried various distances from north to south, being often depos- 
ited at higher elevations than the localities from which they were 
brought. These glacially transported shells and fragments of shells 
cannot therefore be regarded as proof of the former presence of the 
sea at the height where they are found. 
So long ago as during the Revolutionary war a fort was built 
on the top of Telegraph hill in Hull, near the extremity of the pen- 
insula of Nantasket, and a well was dug inside the fort, of which 
the commander, Gen. Benjamin Lincoln, wrote as follows. J “There 
Geographical Gazetteer of the Towns in the Commonwealth of Massachusetts, 1785, 
p. 56. (Only a small part of this work was published.) 
