DENTALIID^. 113 



of living individuals, soon destroy them. Lacaze-Duthiers 

 observed a current of water passing through the shell from the 

 opening at the smaller end. He discovered the Dentalium at 

 low-water mark, where its presence was betrayed by a small 

 groove in the sand ; and he seems to have got a knack of finding 

 them, for he says he easily procured 200 live specimens at the 

 recess of a single high spring-tide. They prefer certain spots, 

 especiall^^ patches of coarse sand mixed with broken shells and 

 interspersed with Zostera. The Dentalium is hardy, and appar- 

 ently abstemious. Lacaze-Duthiers kept some alive in a flask of 

 sea-water with a little sand for more than eighteen months. It 

 is much more active at night, and sensible of light. A ray of 

 the sun or the flame of a candle will cause it to withdraw its 

 foot. This organ acts as a piston in expelling at the other end 

 the eggs and seminal fluid, as well as, perhaps, the faeces and 

 exhausted water. The point of the young shell is pear-shaped, 

 and bears some resemblance to a baby's feeding-bottle with the 

 hole at one end instead of in the middle. It is broken off" when 

 too small to contain the terminal tube or process of the mantle ; 

 and this part of the shell is continuall}^ rubbed away as the 

 animal increases in size, until at last it becomes truncated, and 

 a short pipe is formed with an oblique slit in front to accommo- 

 date the terminal tube. The slit is extended in certain species, 

 although this distinctive character is confined to adult specimens. 

 The inside of the shell is white as porcelain, and brilliant as 

 varnish. The epidermis is slight and easily abrades. The micro- 

 scopic structure of the shell is scarcely difi'erent from that of 

 Patella. It is most complicated, being composed in a great 

 measure of prisms, interlacing fibre, and anastomosing canals— 

 not of cellular elements. The quantity of animal matter which 

 it contains is next to nothing. 



" Mr. Lord says that these shells were employed as money by 

 the Indians of Northwest America before the introduction, by 

 the Hudson's Bay Company, of blankets, which to a great extent 

 superseded the tooth-shells as a medium of purchase. ' A slave, 

 a canoe, or a squaw, is worth in these days so many blankets ; 

 but it used to be so many strings of Dentalia.' The value of a 

 Dentalium depends upon its length. Twent^^-five long shells, 

 strung together end to end, make a fathom, and are called a 

 ' Hi-qua.' At one time such a string would have been worth 

 about £.50 sterling. The shells inhabit the soft sand, in the snug 

 bays and harbors that abound along the west coast of Yan- 

 couver's Island, at a depth of from 8 to 5 feet. The habit of the 

 Dentalium is to bury itself in the sand, one end of the shell being 

 invariably downwards, and the other end close to the surface. 

 'This position the wil}^ saA^age turns to good account, and has 

 adopted a most ingenious mode of capturing the much-prized 



