GASTEROPODES. 287 



size, place, or approximation. They are detached, either when together 

 or asunder. 



PLATE XLI. 



FIG. 1 . Tritonia pinnatifida, adult, profile. 



2. Back. 



3. Belly. 



4. Branchial tuft, enlarged. 



5. Spawn. 



The distinctions among these animals are so slight, as to impair our 

 confidence when desirous of constituting different species, for which it is 

 easy to mistake mere varieties. Such should be named rather indefinitely 

 or provisionally, so that they may fall out of the list, without leaving any 

 hiatus of consequence. 



2. TRITONIA PUNCTATA. The Speckled Tritonia. Plate XLI. Figs. 6, 7, 8. 



This species presents some striking analogies with the preceding. 



Length seven lines ; branchial tufts, five, six, or seven pair, accord- 

 ing to the age and dimensions of the specimen. In one about three lines 

 long, with five pair, the longest tufts consisted of three circumferential 

 stages. These successive stages are not quite so definite as in the pre- 

 ceding. The tentacula resemble the former : the sockets are very dila- 

 table ; and the animal shews great power over their form. A black speck 

 is situate at the root of each. The colour of specimens is white, speckled 

 with red ; and sometimes so very profusely, that the back seems almost 

 uniformly stained by it. 



A quantity of spawn, of much the same general character as the 

 preceding, but less regular, was deposited by a specimen, about half an 

 inch long, with six pair of tufts, on 14th April, which had hatched in 

 eleven days. 



This is a beautiful animal, whenever the variety of speckling of 



