95 CONTRIBUTIONS 
I am not aware of this genus having been found in 
a fossil state in Great Britain. M. Deshayes gives us three 
for the Tertiary on the continent. Dr Morton has observed 
one, C. costata, in the Tertiary of St Mary’s, Maryland, 
and Mr Conrad obtained two in the Upper Marine Forma- 
tion of Maryland, viz. the convera and glauca, both of 
which Mr Say obtained in a living state on our coast. 
Mr Conrad has also described a species, the lirata, from 
Claiborne. 
FAMILY BULL/AZANA. 
GENUS BULLA. Linneus. 
B. St Hillairii.* Plate 4. Fig. 78. 
Description. Shell cylindrical, transversely striate ; sub- 
stance of the shell rather thick ; spire truncate and umbi- 
licate ; whorls somewhat compressed in the middle ; co- 
lumella thickened at the base ; mouth linear, wider at the 
base ; outer lip sharp. 
Length .7, Breadth 5-20ths, of an inch. 
Observations. This species resembles the figure of Sow- 
erby’s constricta.t Ours is wider at the base, and the base 
* Named after the enlightened traveller and naturalist Geoffrey St 
Hillaire. 
+ Min. Conch. plate 464, fig. 2. 
