298 Dr. Philippi on the Animal q/" Astarte incrassata. 



a short description of it in his ^ Osservazioni Zoologiche/ 

 (No. II. May 1833, p. 15.) which are but Httle known. His 

 statements perfectly agree with my observations, with this one 

 exception, that I cannot find the large reddish brown spot 

 which he saw on the mantle in the region of the umbones. I 

 must also fully subscribe to his views upon the systematic 

 classification of the animal which he adds to his description. 

 The description proves that the animal of Astarte has no re- 

 semblance to that of Venus, as was supposed from the consti- 

 tution of the shell by Cuvier, ^ Regne Animal/ edit. 2. vol. iii. 

 p. 150, and Rang, ^ Manuel de Malacol.^ p. 314, and Deshayes 

 in Lamarck, ^ Hist. d. Anim. sans Vert. ^ edit. 2. vol. vi. p. 256, 

 but on the contrary it quite agrees with Cardita. 



I cannot help remarking on this occasion, how frequently 

 the laws of analogy which we expect to find between animal 

 and shell fail in the Molluscs. Whilst in the vertebrate ani- 

 mals,'almost without exception, a similar osseous skeleton, and 

 even some similar bones, necessarily belong to animals which 

 are also similarly formed in their other systems, we find that 

 in very many cases this is not so in the molluscs. To quite 

 similarly formed shells belong animals of decidedly different 

 structure. I only refer to Vermetus and Serpula, Sigaretus 

 or Coriocella, and Cryptostoma"^ and Buacinum, Lamk., where 

 B. undatum is hardly distinguishable from Fusus antiquus by 

 anything but its black spots, whilst B, Linnm and B. macu- 

 losum agree with Purpura, Columbella and Mitra ; and many 

 other species, as B, mutabile, greatly differ from both men- 

 tioned forms ; lastly, Fusus and Pleurotoma, On the con- 

 trary, a very similar animal often inhabits very dissimilar shells. 

 I will mention for example Achatina and Carocolla, Mitra and 

 Purpura, Cerithium and Rostellaria pes pelecani, Cardita and 

 Astarte, &c. 



I have still one correction to add concerning the synonyms 

 o^ Astarte incrassata. I formerly added to this the Venus Dan- 

 moniensis and V. sulcata of English authors ; but my friend 

 M. Koch has pointed out to me that the English species is 

 decidedly distinct. M. Deshayes also in his second edition 

 of Lamarck, represents the Astarte incrassata ( Venus incras- 

 * See note in the following article, p. 307. 



