274 BULLID^E. 



and the Philine of Ascanius, adopted by M. Loven, with 

 Bullaa : though these ancient titles may have priority of date, 

 still, whatever injustice may be done and it would appear, 

 from the want of support of these genera, that it cannot be 

 great it is impossible at this time of day to dispense with the 

 Bulla of Linnseus and Lamarck, and the Bullaa of the latter, 

 which have been so long in use and universally acknowledged. 

 I have given a general and anatomical description of Bulla 

 hydatis from many live individuals, which have enabled me to 

 verify the observations of M. Cuvier, to fill up some gaps, and 

 I believe to correct some errors, which, for the reasons I have 

 assigned below, have escaped the attention of that prince of 

 anatomists. 



* Shell external. 

 BULLA, Linnaeus. 

 B. HYDATIS, Linn, et Auct. 

 E. hydatis, Brit. Moll. iii. p.530, pi. 114. D. f. 7; (animal) pi. U.U. f.3. 



Animal, when fully extended, of an elongated oval shape. 

 The upper or tentacular lobe, and that of the foot, with its 

 reflected portions, are of a pale yellow, aspersed with very 

 minute, close-set, sand-like, dark mouse or lead-coloured 

 points throughout their external surface; the spots on that 

 part of the mantle covered by the shell are larger and of 

 intenser hue, so that the animal has altogether the aspect of 

 being clothed in a close-sprinkled pepper-and-salt jacket. 

 The sinus around the body, which divides the upper and lower 

 lobes, is of a pale yellowish-white colour. The tentacular 

 lobe of the head is small, of subquadraiigular form, a little 

 narrowed behind, where, as well as in front, it is gently 

 sinuated, with slight emarginations at the centre of both 

 ends, which by no means give their right and left extremities 

 any pretension to be styled four tentacula, agreeably to M. 

 Cuvier's view. The true mantle extends to the posterior part 

 of the tentacular lobe, with its thickened rounded margin 

 swelling out a little beyond the periphery of the aperture of 



