DENTALIUM. 453 



entails^ seventeen lines being above tlie standard length of 

 the species in Great Britain. The broader end of an indi- 

 vidual of that size measured the fifth of an inch. Worn 

 shells may not unfrequently be separated from the pre- 

 ceding species (which, by the bye, is peculiarly apt to 

 display erosion at the narrower end) through the occasional 

 appearance of an annular substratum of colouring matter at 

 that extremity. A kind of articulated appearance is some- 

 times produced through the strise being crossed by chalky 

 rings of growth. 



An examination of the original types of Turton's de- 

 scriptions, most kindly forwarded to us by Mr. Jeffreys, 

 has enabled us to determine the dentalis, labiaium, and 

 politum (subsequently changed to lave) of that author with 

 positive certainty. The first is the immature state, the 

 second the truncated adult, with its reparative tube in 

 perfection, whilst the third was constituted from dead and 

 worn individuals of the last mentioned form. Mediter- 

 ranean examples of Tarentinum are more elongated in 

 proportion than the British ones, and their strise occupy 

 a larger portion of the entire surface. 



As the name entails more properly belongs to the 

 northern shell, we have adopted that given by Lamarck to 

 a variety of this species. Da Costa's name of vulgare is 

 certainly j)rior, but it was given with the idea of ejecting 

 the LinnaDan name of a species that he considered at the 

 same time to be identical with his own. The marked ill- 

 will towards Linnajus and his nomenclature so pertina- 

 ciously displayed both in his conversation and in his 

 " British Conchology," arose from his baffled desire of being 

 admitted, through the influence of Linnteus, to an honorary 

 membership in a Swedish Natural- Historical Society.* 



* Smith's Correspondencf of Linnaeus. 



