9 



mcnclature, 1 have inserted the name of comvlanatus to the 

 shell described by Mr. Say under the name of purpureas." — 

 (Trans. Philos. Sc. Vol. 3, N. S.) 



I have not, at present, the means of referring to Dillwyn's 

 work, and I can therefore only speak in relation to Lis 

 figures, t. 15U, above mentioned, and consequently, to an. 

 scription founded on those figures. On reading the above. I 

 was myself struck with the singularity of the fact, that I should 

 have overlooked the similitude, if any, between the shell and 

 a figure with which I was equally well acquainted. But on a 

 re-examination of the figure, I am in my turn surprised that 

 any one should have thought of bringing the purpura!.; into 

 comparison with it. How that figure can appear so different- 

 ly to different conchologists, I know not; but certain ii; is that 

 Gmelin quoted it, with a saving mark of doubt, for Mytilus 

 cygneus! ! I quoted it in the year 1819 for Unto crassus, Barnes 

 also quoted it for the U. crassus, and now it is supposed to re- 

 present the shell in question. 



After a careful comparison of the shell with that figure, I 

 cannot, with any moderate concession of character, ma! 

 correspond; and, moreover, I cannot think that any one will 

 be more successful in this respect than I have been. But even 

 if a strong likeness really existed, two words of Lister's de- 

 scription, quoted by Mr. Lea himself, pu's the matter altoge- 

 ther beyond a doubt. The words, " admodum i ." en- 

 graved on the same plate with the figures, admit of no miscon- 

 struction, and no approximation of the purjn \ hich Air. 

 Lea says, p. 33, note, •• is never ponderous,''') but agree 

 well with a variety of the unfortunate U. crussus; for which f 

 originally quoted the figures, and which is 

 For these reasons, I think that cause has not yet b<„-. 

 why the name should be changed; and, therefore, agre 

 to any rules of modern nomenclature, the name , 

 seems fated to withstand all attacks, unless, indeed, it can be 

 proved, from Mr. Dillwyn's description itself, that h<- m 

 this shell, when he described his complanatus. 

 the figure to which he refers. 



ALASMODO N T A . 



A. sculptilis. Shell transversely suboval, y 

 tions: umbo and summit with six or seven rathei liga- 



tions, which are transverse, rectilinear, at tl 

 ruptly arquated or reflected: flnrsal and ant riot 



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