belonging to mollusks having their fleshy parts much developed in folds. 

 The foot is lobed behind and reflected over the spire of the shell ; the sides 

 are lobed in a manner sufficient to envelope doubly the shell, the lobes 

 acting sometimes as fins, and in some instances even the tentacles are 

 modified into an anteriorly-reflected lobe, the eyes being either indistinct 

 or wanting.* All these variations afford good distinctive characters for 

 the determination of groups. For the conchologist it will suffice to follow 

 the Lamarckian plan of including them in a single family and genus. 



The Bulla dwell mostly in depths of from one to thirty fathoms, seldom 

 appearing above low water-mark, and a few, such as B. hyclatis, live in 

 brackish water. Their shells are mostly of a delicate hyaline substance ; 

 but some of the larger and firmer species, frequenting our own shores, and 

 a few among the exotic forms, are brilliantly painted. 



Forbes and Hanley include the operculated genus Tornatella in this 

 family ; but a consideration of the foreign species of that genus would 

 seem to argue that the alleged affinity is more fanciful than real. 



1. acuminata, Bing. 



2. alba, Brown. 



.'!. albocincta, Iloev. 



4. Algivsc, Adams. 



5. alicula, Ehren. 



6. Adansoni, Phil. 



7. ambigua, Adams. 



8. ampulla, Linn. 



9. amygdalus, List. 

 f 0. arachis, Quo?/. 



11. aspersa, Adams. 



12. angustata, id. 



13. australis, Quoy. 



14. bicincta, id. 



15. biplex, Adams. 



16. biplicata, id. 



17. bizonia, id. 



18. Borneensis, id. 



19. brevissima, id. 



Species. 



20. brevis, Quoy. 



21. Bruguieri, Adams. 



22. bullata, Mull. 



23. canaliculata, Say. 



24. castanea, Adams. 



25. catena, Moid. 



26. Cecillii, Phil. 



27. cinctella, Adams. 



28. coarctata, id. 



29. concinna, id. 



30. concentrica, id. 



31. constricta, id. 



32. Coreanica, id. 



33. corticata, Mull. 



34. Cranchii, Leach. 



35. cruentata, Adams. 



36. Cumingii. id. 



37. curta, id. 



38. cylindracea, Tenn. 



39. cylindrica, Hell. 



40. cymbalum, Quoy. 



41. debilis, Gould. 



42. decussata, Adams. 



43. dentifera, id. 



44. ebumea, id. 



45. elegans, Gray. 



46. elongata, Adams. 



47. exigua, id. 



48. ferruginosa, Chemn. 



49. flavescens, Adams. 



50. fusca, id. 



5J. fusiform is, id. 



52. glabra, id. 



53. glauca, Quoy. 



54. Gouklii, Courlh. 



55. gracilis, Adams. 



56. Guildingii, Swains. 



57. Hanleyi, Adams. 



* Mr. Arthur Adams, speaking of the Bulla Coreanica, says, " There are no visible eyes or 

 tentacles, and its elongated head probes with its extremity the mud-ilats on whieh the species 

 abounds, for the small bivalves which constitute its food. Some of the large mud-flats among 

 the C'orean Islands were covered with these shapeless mollusks, and afford tempting morsels to 

 the grallatorial birds seen striding over the mud. The Bulla soluta appears to be blind, while 

 I lie head is very elongated, and the side lobes of the foot well developed for swimming, which 

 faculty this form enjoys in great perfection." — Moll. Jo//. Samarang, p. 65. 



