SUPPLEMENT. 1221 



by means of the horned beak that they can protrude at 

 will. 



3. ECHIXODERMATA (STARFISH, SEA-URCHINS, &C.) 



Starfish are probably the most pernicious and per- 

 sistent enemies of oysters. In the estuary of the Thames 

 they are locally known as five-fingers, and they abound on 

 many of the Kentish beds, in fact, in greater or lesser 

 numbers, they may be said to be constantly found attendant 

 on all oyster-beds Though known as " five- 

 fingers," starfish are found frequently with only three arms, 

 at other times there are as many as ten, and foreign varie- 

 ties have from twenty to forty tentacles. 



. The arms are covered on the upper sides 

 with a tough skin, so tough indeed that, when a " clock " 

 which had a five-finger as an inhabitant was stamped on, 

 the shells were broken to pieces, and, though one of the 

 five-finger's arms was outside the edges of the shell, it was 

 not separated, and only slighted indented, (a) 



Starfish are sometimes of use on an oyster- 

 bed, from the preference they'show, already mentioned, of 

 attacking mussels, annelids, and even acorn-barnacles, 

 before oysters. So that, when there is much of this kind 

 of vermin on a bed, the five-fingers may be allowed a little 

 "law"; but their employment in this manner should be 

 carefully and judiciously watched, and certainly not allowed 

 on grounds where the owners have not the means of 

 promptly exterminating them as soon as they have eaten 

 clown to the ovsters. 



j 



Five-fingers are much more plentiful on the south banks 

 of the Thames than on the north side, whilst whelk-tingles 



(a) Clock is the name given to the double oyster-shell after the 

 fish is dead and has become removed. 



