108 Mr. W. Clark on the Muricidse. 



XII. — On the Muriciclse. By William Clark, Esq. 

 To the Editors 0/ the Annals of Natural History, 



Gentlemen, Norfolk Crescent, Bath, December 1, 1850. 



Some of your readers may feel an interest in the following 

 malacological notes on the British Muricidce, which are now 

 distributed in Murex, Buccinum, Fusus, Pleurotoma, Purpura, 

 Nassa, Tr-ichotropin and Cerithinpsis ; these genera form a part of 

 Lamarck's Canalifera and Purpurifera. This family is of enor- 

 mous extent, and has its origin in the Linnsean genera Murex 

 and Buccinum, which, though sepai-ated by Liunjeus on artificial 

 grounds, have their animals identical in all essential points ; and 

 it can scarcely be doubted, with the views held by that great na- 

 turalist, that if he had been aware of their similar malacological 

 structure, he would have merged the Buccina in Murex, or vice 

 versa : we shall therefore consider them synonymous ; they have 

 been split by the moderns into numerous genera on pure con- 

 chological bases. Many causes have concurred to produce this 

 artificial arrangement — amongst them, the multitude of species, 

 the dissimilarity of the hard parts, which malacologists failed to 

 see in their true light as the indices of species, but chose to con- 

 sider the variable forms to proceed from generic animal distinc- 

 tion. We will examine these points, and endeavour to reduce 

 them to their proper value. 



The principal distinctions between this division and the Holo- 

 stomata are, that the periphery of the aperture of the shells of the 

 Canalifera is broken into branchial canals and more marked and 

 extensive depuratory sinuses, and in the soft parts having the 

 invariable presence of a retractile proboscis, with some other 

 variations that will be mentioned. The shells are of elegant 

 structure, and the animals of great beauty, but the latter resemble 

 each other so much as to set generic distinction out of question, 

 and even to render specific characters difficult without the aid of 

 the hard parts, on which account I am obliged to enter into 

 greater minutiis than perhaps may be thought necessary. It will 

 also be shown that the anatomy as well as the hard and soft parts, 

 with the general characters of the coloration, especially in the 

 minor Murices, are all but identical. 



There is a singular coherence in the specific descriptions ; this 

 arises from the similarity of the objects ; but if, to relieve the 

 tsedium of the "iterumque, iterumque," I had attempted a ge- 

 neralization beyond what has been admitted, confusion would have 

 resulted from the destruction of the individuality of the objects 

 by amalgamated descriptive characters ; the account would rather 

 be that of a compound than of an individual animal, and the 



