580 BULLIDiK. 



BULLA. LiNN-EtTs. 



Shell ventricose, subglobose, oblong, inflated, convolute; 

 spire involute ; surface smooth, striated or punctate ; aper- 

 ture narrow superiorly, ovate below. No operculum. 



Animal bulky, partially investing but not covering the 

 shell ; capital lobe large, truncated in front, bilobed pos- 

 teally, furnished (except in B. Cranchii) with immersed 

 eyes towards the centre of the disk ; lateral lobes wery 

 large, reflected on shell ; a more or less developed caudal 

 lobe reflected on the spire ; foot large quadrate, extending 

 beyond the shell posteriorly; gizzard armed with calcareous 

 plates ; tongue without axile plate, but armed with numer- 

 ous laterals ; branchial plume single. Individuals her- 

 maphrodite ; male organ retracted. 



The animals of this genus are capable of swimming with 

 ease by means of their large lateral lobes, whilst their 

 extensive foot enables them to crawl with equal facility. 



B. HYDATis, Linnaeus. 



Oval-globose, extremely thin, merely undulated spirally by 

 very minute and crowded simple striulre ; usually covered with 

 a yellowish skin. 



Plate CXIV. D. fig. 7, and (Animal) Plate U. U. fig. 3. 



Bulla hydutis, Linn. Syst. Nat. ed. 12, p. 1183, probably. — Pulteney, Hut- 

 chins, Hist. Dorset, p. 40. — Donov. Brit, Shells, vol. iii. pi. 88. 

 —Mont. Test. Brit. vol. i. p. 217, vign. 1, f. 1 to 4 ; Suppl. 

 p. 94, animal. — Maton and Rack. Trans. Linn. Soc. vol. viii. 

 p. 123. — Rack. Dorset Catalog, p. 43, pi. 23, f. 10. — Turt. 

 Conch. Diction, p. 20. — Flemino, Brit. Anim. p. 292. — Brit. 

 Marine Conch, p. 139. — Brown, Illust. Conch. G. B. p. 57, 

 pi. 19, f. 29, 30.— Brug. Encycl. Meth. Vers, vol. i. p. 374.— 

 CuviER, Ann. du Mus. vol. i. pi. 12, f. 11 to 14 and 21. — 



