FAMILY I. TROCHOIDA. 
GENERA. 
4; Turbo. Lin. ; 
Shell turbinated, mouth 
round. 
a. Turbo, Lam. (1) 
Membranous wings 2 Long tentacula. Eyes on stems at the 
on the side of the foot. outer bases of the tenta- 
ltrs ap. 6, 7,8, 9, cula. 
10. 
6. Delphinula, Lam. 
c. Vermicularia. PI. 
19, fig,8. 9. 
Marine. 
2 Triangular, flattened, _—_ Ditto. 
small tentacula. 
d. Turritella, Lam. 
e. Scalaria, Lam. (2) 
Pl. 17, fig. 4. 
2 Long, slim tentacula. _Ditto. 
(1) To these belong the thick, strong opercula, so frequently found in collections, 
which were formerly employed in medicine under the name of unguis odoratus. 
(2) The mouth is encircled by a callous pad, which the animal repeats from 
space to space as its shell increases, so as to give the appearance of ladders, 
