A. E. Verrill—Post-pliocene fossils of Sankoty Head. 369 
previously been found south of Cape Cod. Modiola hamatus, 
which occurs in considerable numbers in the lower bed, is a 
southern shell, common in the Gulf of Mexico, and on the 
southern coast as far north as Virginia, but occurring on the 
southern coast of New England, only locally, in harbors, etc., 
and generally on beds of oysters that have been transplanted 
from farther south. For this reason it has been generally sup- 
ee that it is not indigenous but has in all cases been intro- 
uced with the oysters. However this may be now, it is evi- 
dent that it was a native species in Post-pliocene times. 
The only species that shows any noteworthy variation, when 
compared with the modern shells from the same region, is the 
List of Species JSrom the lower Shell-bed. 
The names of the species are those used in the Report on the 
Invertebrata of Southern New England, by the author and 
Prof. S. L Smith, in 1st Report of the United States Com- 
missioner of Fish and Fisheries, 1874. 
AM. Jour. Sot.—Tutrp — Vor. X, No. 59.—Nov., 1875. 
