54 



being elongated at their extremities, and not being dentated on their 

 left side, seemed to constitute a distinct genus : these he has, therefore, 

 collected under this genus, of which I do not know that any have been 

 found fossil. 



XL Terebdlum. A convoluted univalve, with an acute apex. The 

 opening longitudinal, narrow upwards, notched at the base, and tooth- 

 legs. The columella truncated. 



Bulla terebellum of Linnaeus is also separated from the genus Bulla by 

 Lamarck, who observes that it approaches nearer to Strombus than to 

 Bulla ; it differing from the latter in the notch at the base of its opening, 

 and by the columella being, as it were, truncated at its lower part, as 

 in Strombi. 



A fossil shell of this genus is figured by Brander, Fossil hauton. Tab. i. 

 Fig. 29, a. and Tab. vi. /. 75, as one of the Hampshire fossils, and 

 named by Solander, Bulla sopita et volutata. It is a thin subcylindrical 

 shell, with no spire. A shell of the same species, named by Lamarck 

 Terebellum convolutum, is found in considerable number at Grignon ; 

 and, notwithstanding their very fragile nature, many are found in a per- 

 fect state, proving that they must have lived in the region in which they 

 are found. The recent analogue of this shell is not known. Another 

 species, T. fusiforme, is also found in the environs of Paris. 



XII. Oliva. A subcylindrical univalve, notched at its base. The 

 turns of the spire separated by a channel. The columella striated 

 obliquely. 



The genus Valuta, of Linnaeus, comprehends many shells, the cha- 

 racters of which certainly require their separation into other genera. 

 This has been accomplished by Lamarck with much care. Oliva is 

 a genus which he found necessary thus to form, Linnueus having consi- 

 dered all the olives as only varieties of one species of volute, which he 

 named Voluta oliva. 



Lamarck describes three species of this genus found in the neighbour- 



