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 in 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 in the genus Bulla. 

 The Bullida, like the Helitida, are hermaphrodites with 

 mutual congression, and are oviparous. 



Of this section the animals of the following Bulla have not 

 been met with : 



B. LIGNARIA, Linnaeus. 



Scaphander lignaria, Brit. Moll. iii. p. 536, pi. 114. F. f. 3; (animal) 

 pi. V.V. f. 5. 



B. OBTUSA, Montagu. 

 Cylichna obtma, Brit. Moll. iii. p. 512, pi. 114. C. f. 1, 2, 3. 



B. UMBILICATA, Montagu. 



Cylichna umbilicata, Brit. Moll. iii. p. 519, pi. 114. C. f. 9. 

 C.nitidula, Brit. Moll. iii. p. 515, pi. 114. C. f. 6. 

 C. conulus, Brit. Moll. iii. p. 517, pi. 114. C. f. 7. 

 C. strigella, Brit. Moll. iii. p. 518, pi. 114. C. f. 8. 



B. AKERA, Gmelin, Mont, et nobis. 



Akera buttata, Brit. Moll. iii. p. 527, pi. 114. D. f. 4, 5, 6; (animal) 

 pi. V.V. f. 6. 



B. CRANCHII, Leach. 



B. Cranchii, Brit. Moll. iii. p. 533, pi. 114. D. f. 8, 9; (animal) 

 pi. V.V. f. 2. 



B. HYALINA, Turton. 



Amphisphyra hyalina, Brit. Moll. iii. p. 521, pi. 114. D. f. 1, 2; 

 (animal) pi. U.U. f. 2. 



