ITNIV ALVES. DENTALIUM. 145 



talium entr.lis or dog's-tooth-shell, which is nn inhabi- 

 tant of tlie Indian and European shores, and is generally 

 an inch and a half long, of a reddish or pale yellow co- 

 lor, with the tip often tinted with orange or pink. The 

 Dentalium pellucidum is of a horny or pale honey color, 

 very narrow and thin, and does not effervesce with acids. 

 It is an inhabitant of the North seas, and about two 

 inches and a quarter long. 



The Dentalium minutum inhabits the Mediterranean ; 

 it is a round, straightish, smooth shell, and so very minute 

 as scarcely to be discernible by the naked eye ; it resem- 

 blesa small bristle, or one of the spines of an echinus. 



The Dentalium imperforatum (from Sandwich and 

 its neighbourhood) is also a minute species, and is by no 

 means common. 



The fossil species of the Dentalia are as follow, viz. 

 Dentalium sexangulum, and Dentalium fossile, both 

 from Loretto; and the Dentalium annulatum, radula, 

 interruptum, and vitreum, are the sub-terrestrial products 

 of Piedmont. 



The recent species are mostly from the Indian and Eu- 

 ropean oceans ; though some few are from the Mediter- 

 ranean and Northern seas, and one species inhabits the 

 shores of Africa. 



DENTALIUM.-Tooth-Shell. 



Elephantinum {FAephart' s-tooth Shell.) Fasciatum. 



Aprinum. Rectum. 



Arcuatum. Fo$sile. 



Striatulum {Striated T. S.) Annulatum. 



Sexangulum. Radula. 



Dentalis. Interruptum. 



