tiEPOKT OF ('()Mmissi()m:us of inland fish KIM i<:s. 21 



the stomach of the star-fish, and the margin of the shells shows no 

 trace of having been acted iij)on by an acid. A considerable 

 qnanlity of acid would be required to sufficiently dissolve the 

 shell of a medium sized oj^ster, and this would undoubtedly dis- 

 solve, at the same time, the unprotected calcareous spines about 

 the mouth of the star-flsh itself. 



The most prevalent opinion is, perhaps, that the star-fish chips 

 away the thin edges of the shell until an entrance is gained to the 

 soft parts. The broken edges of the oyster shells Avhich have been 

 opened by the star seem at first to sustain this opinion. The pro- 

 cess is thus described in a recent number of a Providence news- 

 paper. "The star-fish seizes its prey by clasping its tentacles 

 around the'soft, f ringy edge of the oyster, which it eats away until 

 the soft oyster can be sucked from the orifice, etc." Ingersoll, in 

 an article on Oyster Industry, already referred to, after speaking 

 of the alleged use of acid in opening the shell, saj^s :-— " Moreover, 

 it seems unnecessary, since the appearance of every shell attacked 

 at once suggests the breaking down, chipping off movement, which 

 the star-fish might easil}^ i)roduce by seizing and suddenly pulling 

 down with the suckers nearest the mouth, or by a contraction of 

 the elastic opening of the stomach. At any rate the thin edge of 

 the shell is broken away until an entrance is made which the 

 oyster has no way of barricading." 



An oyster which has not been injured by rough treatment has 

 the edges of the shell extremely thin and so fragile that they can 

 be broken down with a camel's liair brush. The lower shell is 

 particularly fragile near the edge. It will be noticed, however, 

 that the valves frequently do not come together at all at the ex- 

 treme edge, and the real line of contact, the biting edge, is one- 

 fourth inch or more further back. The chipping of the margin of 

 the shell by the star-fish is merely accidental, and avails nothing 

 in getting at the soft parts of the oyster. I have carefully ex- 

 amined a large number of shells of oysters known to have been 

 devoured by star-fish, and, though they appear to be badly chipped, 

 the biting edge is never broken, and the shells have always been 



