] 02 Mr. W. Clark on the Animals of the Biillidse. 



loose muscular straps ; they however spring from two small yel- 

 low spongy or granular bodies, situate on the upper part of the 

 gizzard; these I presume are the salivary glands; if so, the 

 straps are the excretory ducts. They lie on each side the oeso- 

 phagus in the most lax manner : I should have called them oeso- 

 phageal, gizzard and buccal mass retractors, as they are connected 

 with all these organs, if M. Cuvier had not determined them to 

 be salivary glands ; but he is in error in stating, " L'hydatis les 

 a tres longues, inegales, et celle du cote gauche fourchue par 

 son extremite posterieure.^' We have in our cabinet perfect pre- 

 parations of these organs, and can positively state that they are 

 of the same length, entirely symmetrical, with both ends fixed to 

 the gizzard and posterior part of the buccal mass ; they do not 

 float loose of different lengths and forms, as are represented in 

 pi. 2. fig. 14. of M. Cuvier's memoir. Having dissected nume- 

 rous specimens we are quite sure on this point. Though we ad- 

 mit the straps to be the salivary glands, sub fide Cuvieri, still we 

 are much astonished that that great naturalist has not noticed 

 the very visible dendroid leaflets on each side the mouth ; we 

 must consider them an additional pair of salivary glands : some 

 mollusca have an upper and lower pair, and these would appear 

 to be more adapted for such purpose than the slender sti*ap- 

 shaped filaments. I can only account for their not being noticed, 

 on the su])position that the glandular leaves in M. Cuvier's spe- 

 cimens must have been so discoloured by the spirit as to have 

 escaped attention. One word more on them : as they are situated 

 exactly at that part of the groove which corresponds with the 

 position of the oesophageal ganglions, it is possible that as these 

 nervous masses are of larger volume than I ever saw in any other 

 gasteropod, the glandular leaflets may excrete a liquor to invi- 

 gorate and minister to the nervous influences : this is a mere 

 conjecture : I would certainly incline to think them salivary 

 glands. 



Having mentioned the nervous system, it may be as well at 

 once to notice it, as M. Cuvier scarcely alludes to it. From the 

 point where the oesophagus commences at the posterior part of 

 the buccal mass, it has on each side of it two distinct orange or 

 lemon-colour large oval ganglions, each pair being connected by 

 very strong threads, and the under part of the cordon is formed 

 by two minute round orange ganglions — strange to say, fixed on 

 the posterior part of the buccal mass, and connected by threads 

 with the upper ganglions ; these, when in situ, form a complete 

 cordon of six medullary masses ; from this circle exceedingly 

 strong nervous filaments radiate to the head, the verge, and all 

 the anterior parts of the body. The ganglionic cordon is con- 

 nected with two large stomachal lemon-colour ganglions, which 



