SOME COASTWISE FISHES. 121 



frequently exposed on our market-stalls. The 

 purse, or ' shark-barrow,' as it is termed in Eng- 

 land, is the egg-capsule of this singular creature, 

 by whom it is deposited in the forest of sea-weed, 

 to be there safely anchored by one or more of its 

 filamentous processes. 



The rays or skates (Raia) are not uncommon 

 along our coast, where they occupy the bottom 

 water, skimming about just over the sand or mud. 

 Their flabby masses are occasionally stranded on 

 the beach, where they are soon picked to pieces by 

 the ever-watchful sea-fowl in search of such deli- 

 cacies. Of the remaining cartilaginous skeleton, 

 the jaws, whose small pavement-like teeth emi- 

 nently serve the purposes of grinding, generally 

 remain the longest, and are often found still at- 

 tached to each other when nothing else remains. 



Somewhat similar jaws, but with the teeth sharp 

 and pointed, instead of flat and pavement-like as 

 in the rays, are the belongings of true sharks, sev- 

 eral species of which wander about our shores. The 

 commonest of these is the sand-shark or shovel- 

 nose ( Carcharias Americanus), an exceedingly vora- 

 cious animal, measuring when full grown some 

 six or seven feet. The teeth are sharp and awl-like, 

 whence the name Odontaspis applied to the genus 

 by many naturalists. In the majority of the sharks 

 the teeth are disposed in several distinct series, but 

 only those of the outer row are functional at any 

 one time. When these are lost they are imme- 

 diately replaced by the teeth of the second series, 

 which, as well as the remaining teeth, are articu- 



!■ 11 



