Notes on certain Molluscous and Aquatic Animals. 193 



subgenus of Littorina, as the animals are generically allied. 

 The animal of L. pallidula is white, with two long white 

 tentacula ; the eyes at the external base. 



All the true British Naticae may be referred to the genus 

 Naticina of Guilding, unless the N. tuberosissima of Laskey 

 be an exception. The N. canrena is but doubtfully native. 

 They may be arranged thus: — Genus, Naticina Guilding: 

 Species 1. monilifera Lam., synonyme, glaucina Mont., not 

 of Lin. ; 2. rufa Mont. ; 3. nitida Donov. ; 4. glabrissima 

 Brown, synon. sulcata Turt.; 5. helicoides Johnston, in Trans, 

 of Berwickshire Nat. Club, 1835; ?6., tuberosissima Mont. 

 Appendix, the fry of the larger species : N. pellucida and 

 alba of Adams. 



In describing the animal of the N. monilifera, I have inci- 

 dentally referred to its tongue. This is an organ on which I 

 am inclined to bestow more importance, in relation to generic 

 character, than has hitherto been ascribed to it. Its form, 

 length, texture, the shape of the expansions at its extremity, 

 and the direction and form of the hooks with which it is provided, 

 are all characters deserving of attention, and constant in re- 

 semblance amongst the several species of each genus, especially 

 amongst the holostomatous tribes of Pulmonibranchia, as well 

 as the Scutibranchia and Cyclobranchia. By the way, I 

 should feel rather inclined to question the statement that the 

 tongue in the Mollusca is worn away at its apex by use. (See 

 an interesting essay on the digestive organs of Mollusca in 

 this Magazine, the Number for February, 1835.) [VIII. 

 71 — 80.] Independent of the somewhat unscientific nature 

 of the supposition, the structure of the end of the tongue 

 would seem to forbid such an idea, especially the constant 

 and precise form of the membranous expansions at the ex- 

 tremity. 



6. Howe Street, Edinburgh, Jan. 1836. 



[Desultory Notes by the late Rev. Lansdown Guilding, relative 

 to Notices in Vols. I. and, II. of this Magazine, on certain Mol- 

 luscous and Aquatic Kinds of Animals. ~\ 



I. 102. The Species of Animals which discharge a coloured 

 or acrid Fluid, are much more numerous than most Persons sup- 

 pose. — The whole of the Laplysiae and the Ianthina slowly 

 pour forth a fluid of the most splendid purple, which serves 

 to darken the surrounding water, and confuse their pursuers. 

 In the Purpura? the fluid is, at first, of milky whiteness, and 

 only by degrees acquires its lovely tints. Other marine 

 beings eject a colourless and pungent secretion, which drives 

 their enemies to a distance. I have seen the Portuguese man 



