BULLA. 285 
shell, in which is fixed a gizzard of three very small, dark 
brown, similar-formed, minutely-dotted, oval, coriaceous plates, 
which can be seen in action through the transparency of the 
basal volution. 
It appears that the only difference between this animal and 
that of B. cylindracea is, that im this the disc-flaps are more 
developed, and the eyes are distinctly visible; I therefore 
consider all the general remarks on the last species, not men- 
tioned to prevent repetition, as applicable to B. truncata, 
which I think is appropriately deposited m the genus Bulla. 
The Bullide, like the Helicide, are hermaphrodites with 
mutual congression, and are oviparous. 
~ Of this section the animals of the following Bulle have not 
been met with :— 
B. rienaria, Linneus. 
Scaphander lignaria, Brit. Moll. ui. p. 536, pl. 114. F. f. 3; (animal) 
pl. V.V. f: 5. 
B. oprusa, Montagu. 
Cylichna obtusa, Brit. Moll. iu. p. 512, pl. 114. C. f. 1, 2, 3. 
B. umpiricata, Montagu. 
Cylichna umbilicata, Brit. Moll. ii. p. 519, pl. 114. C. f. 9. 
C. nitidula, Brit. Moll. iii. p. 515, pl. 114. C. f. 6. 
C. conulus, Brit. Moll. iu. p. 517, pl. 114. C. f. 7. 
C. strigella, Brit. Moll. iu. p. 518, pl. 114. C. f. 8. 
B. aAKERA, Gmelin, Mont. et nobis. 
Akera bullata, Brit. Moll. iii. p. 527, pl. 114. D. f. 4, 5, 6; (animal) 
pl.aVi.Ved. 6: 
B. Crancuit, Leach. 
B. Cranchii, Brit. Moll. i. p. 533, pl. 114. D. f. 8, 9; (animal) 
pl. VaVof.2: 
B. wyatrna, Turton. 
Amphisphyra hyalina, Brit. Moll. ui. p. 521, pl. 114. D. f. 1, 2; 
(animal) pl. U.U. f. 2. 
