33 
DENTALIUM. TO 0 TH-SHEL L. 
shape form, being full two tenths of an inch wide at the 
larger end, and tapering to hardly the twentieth part of an 
inch at the smaller end, which terminates in a small circu¬ 
lar perforation ; the strife are also much finer, double the 
number of our present species, and stronger at the pointed 
end, whence they gradually lessen, so as to become hardly 
visible at the larger end. Our present shell, which is not 
uncommon on the western coast, tapers very little, and has 
the strirn equally strong throughout, v. v. 
4. Dentalium striatulum. Striated Tooth-shell 
Lister , pi. 647- f- 1, lower fig. 
Dentalium octangulum. Donovan , pi. 162. 
Shell slender, tapering to a fine point, slightly curved, 
semitransparent, open at both ends, with eight longitudinal 
angular ribs, between each of which are three or four very 
obtuse longitudinal striae : color greyish-white, pale rufous, 
or green with a white tip : length about two inches. 
Cornish and Devon coasts : very rare. v.m. 
5. Dentalium labiatum. Proboscis Tooth-shell. 
Shell nearly cylindrical, very slightly tapering and 
curved, semitransparent, ivory white, covered when fresh 
with a black glossy skin, most finely and minutely striatfe 
longitudinally, open at the larger extremity, the smaller 
end truncate, with the flattened surface somewhat undu¬ 
lated in a radiate manner and finely striate circularly, from 
the centre of which projects an oval transparent process 
or lip terminating in an oval aperture, one side of which is 
cloven halfway down: length an inch or rather more; 
breadth'at the open end two tenths of an inch." 
A few specimens of this species have very lately been 
b tough t to us alive, taken by the trawl at Torbay: the ani¬ 
mal is cylindrical, white, with a small central tube at the 
larger end, and a spoon-shaped mouth at the other, r. r. 
6. Dentalium politum. Polished Tooth-shell. 
\ 
I 
Shell somewhat cylindrical, slightly tapering and a little 
curved, semitransparent, quite smooth and finely polished, 
white with generally some irregular grey circular bandj 
.which grow darker and more combined together towards 
the-narrower extremity, open at both ends 3 the smaller end 
very 
