368 Observations on Mr. Stutchburifs 



existence, of an operculum in those species which Mr. Stutch- 

 bury separates from what he calls the true Cassides, and 

 unites under his generic appellation of Cyprsecassis. It is 

 evident, from the above observations, that Mr. Stutchbury has 

 not been aware of several important facts, all of which, as far 

 as they go, are opposed to the separation of the one from the 

 other. Perhaps I may be allowed to suggest that, possibly, 

 Mr. Stuchbury, and his friend Dr. Cutting, may accidentally 

 not have observed the operculum in their examination of C. 

 rufa and C. Testiculus. I mean not to assert that these 

 gentlemen have, from want of giving sufficient attention, left 

 unobserved that which really existed ; but, as Mr. Stutchbury 

 unhesitatingly includes C. coarctata and C. Testiculus, one of 

 which we find has an operculum, and occasionally two varices, 

 and the other of which has sometimes several varices, it ap- 

 pears possible he may have, passed over the operculum of 

 C. rufa. 



Observe, next, Mr. Stutchbury expresses his surprise "that 

 an examination of the shell alone should not have attracted 

 the attention of conchologists to the necessity of making the 

 separation." Upon this part of the subject I have two words 

 to say. First, Lamarck, in his Hist. Nat. des Animaux sans 

 Vertebres, torn. vii. p. 225., under the article Cassis Testiculus, 

 has this observation: — " Ce casque a un pen l'aspect de cer- 

 tains Cyprcca, taut par sa forme oblongue que par celle de 

 son ouverture, qui est etroite : " from which it is evident that 

 Lamarck had observed a degree of resemblance between this 

 Cassis and certain cowries ; though it does not appear that 

 he was possessed of sufficient facts to warrant him in separating 

 it from the other Cassides. Secondly, an examination of the 

 shell alone would not, in my opinion, warrant such a separa- 

 tion ; for, if we were to take the narrow * aperture as the separ- 

 ating character, we should include several which we know to 

 possess opercula, and which have also commonly several varices; 

 and, if we regard those as distinct which seldom or never form 

 varices, we should separate from Cassis, and unite as Cyprae- 

 cassides, some with wide, and others with narrow, apertures. 

 I must now call your attention to a fact which Mr. Stutch- 

 bury, in describing the young state of what he calls Cypras- 

 cassis, taking the C. rufa. as the typical species, has omitted 

 to notice : it is this, that, at various periods of its growth, 

 although it does not reflect the outer lip, as it does in its 

 mature state, so as to form varices, it nevertheless, like several 

 other Cassides, completes the lip on the inner side by form- 



* Which Mr. Stutchbury calls straight, though it really is not so. 



