PUNCTURELLA. HALIOTIS. 2. r >:> 



PUNCTURELLA, Lowe. 

 P. NOACHINA, Linnseus. 



P. noachina, Brit. Moll. ii. p. 474, pi. 62, f. 10, 11, 12 ; (animal) pi. 



B. B. f. 4, 5, 6. 



This Puncturella is a northern and Scotch species, and I 

 believe has not occurred on the southern coasts ; I therefore 

 refer for all that is known of it to the ' British Mollusca/ 

 vol. ii. p. 474, which contains an excellent description of the 

 shell and animal. 



HALIOTIS, Linnaeus. 



H. TUBERCULATA, Linn, et Auct. 



H. tuberculata, Brit. Moll. ii. p. 485, pi. 64 ; (animal) pi. C. C. f. 3. 



This species is the only one of the genus, and cannot be 

 strictly considered indigenous ; it appears to be admitted in 

 the list as an inhabitant of Guernsey, our ancient contiguous 

 dependency. That the eminent French zoologists and com- 

 mentators 011 Lamarck should have stated that Haliotis has 

 the closest alliance with the Trochi, is so extraordinary, and, 

 as I think, so contrary to fact, that I could scarcely believe 

 I had read right. Naturalists, after they have examined 

 this comparative statement, will judge where the error lies. 

 I set out with the invocation, " Cuviernm legitote ! " That 

 illustrious anatomist says, " On pourrait presque dire que la 

 Fissurelle est uii Haliotide " and of course vice versa, I think 

 it will be shown that Haliotis and Trochus are considerably 

 removed from each other. 



This genus presents the first evidence of departure of that 

 symmetry in the shell, which has hitherto characterized this 

 portion of the Gasteropoda ; and in the remaining genera of 

 the group, either in the shell or animal, marks of the iion- 

 symmetrical structure will appear, which will henceforth be- 

 come more and more developed, until the termination of the 

 class. 



Though Haliotis has abandoned the strict patelloid form, it 

 still, by the animal, declares the closest relationship with Fis- 

 surella. 



