DENTALIUM. TOOTH-SHELL. 37 



DENTALIUM. TOOTH-SHELL. 



Shell with a single valve, linear^ tubular, not 

 divided into chambers, open at one or both ends. 



1. Dentalium Entails. Common Tooth-shell. 



Lister, pi. 547. f. 2, and pi. 1056. f. 4 Pennant, pi. 93. 

 f. 6 Da Costa, pi. 2. f. I0--Donovan, pi. 48 Dorset Cat. 

 pi. 22. f. 10. 



Shell slender, tapering, a little curved, opake, glossy, 

 open at both ends, smooth or marked with a few circular 

 striae or obscure annulations : color white or yeilowi$h- 

 white, with mostly a rufous tinge towards the smaller end : 

 length an inch and a half ; diameter at the larger end two- 

 tenths of an inch, and one-fourth as much at the smaller. 



Sandy shores of England and Ireland, v. m. 



2. Dentalium Dentalis. Small Tooth-shell. 



Shell slender, tapering to a fine point, slightly curved, 

 opuke, open at both ends, regularly and closely striate the 

 whole length, the strias thirty or more in number, with 

 often a few faint annulations at the larger end: color 

 white or brownish-white, mostly rufous at the smaller end : 

 length about half an inch. 



On the western coasts : often found in the stomach of the 

 Gurnard, v. m. 



3. Dentalium eburneum. Ivory Tooth-shell. 



Shell a little taper and slightly bent, open at l*oth end?, 

 semitransparent, ivory white but not glossy, often marked 

 with obscure dark purple spots disposed in longitudinal 

 rows, with regular fine raised longitudinal ribs, eighteen or 

 twenty in number, and generally a smaller one between 

 each of them ; the lower end not pointed, with a roundish- 

 oval aperture : length seven eighths of an inch ; breadth at 

 the larger end the eighth of an inch, at the smaller end 

 about half as much. 



This species has been possibly mistaken for the D. Den- 



talis, but may be distinguished at a single glance. The 



latter shell is of a brownish color, and conLal or funnel- 



$ shape 



