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TO GEOLOGY. 117 
small round mouth which is much thickened and reflected. 
The ribs have some resemblance to the multistriata (Say), 
a recent species of our southern coasts, but it certainly is not 
the same species. 
In England the Scalarie have not been found below 
the London Clay. Five have been described from that 
formation, and six from the Crag. The Tables of M. 
Deshayes give twenty-two species from the three periods 
of the Tertiary, which seem there to be nearly equally 
distributed. In the Cretaceous Group of New Jersey, Dr 
Morton discovered a fine species (annulata). Mr Conrad 
mentions two as existing in the Tertiary of Maryland. 
GENUS DELPHINULA. Lamarck. 
D. plana. Plate 4. Fig. 104. 
Description. Shell subdiscoidal, carinate, beneath flat, 
obsoletely and transversely striate, above rounded and 
strongly striate ; substance of the shell rather thin ; spire 
flattened ; suture widely furrowed ; umbilicus wide, cari- 
nate, striate; whorls four ; mouth oblique, round within, 
subangular at the outer edge. 
Length .1, Breadth .2, of an inch. 
Observations. This little species is remarkable for the 
flatness of its inferior portion, for its carina, and wide fur- 
rowed suture. Between the transverse strie and in the 
