Crustacea. 



6691 



strong tin box, which had held biscuits, the lid being secured with 

 wire ; but the crab turned down the edges and escaped. In turning 

 down the edges, it actually punched many small holes quite through 

 the tin ! " 



But Crustacea, upon the whole, must be viewed as carnivorous 

 animals ; and, as I have before remarked, they are occasionally can- 

 nibals, but this only, I believe, when in an extreme state of hunger. 

 Like most Carnivora, the crab does not feed every day ; and perhaps 

 occasionally when it wants food it cannot get it ; then it is that it 

 attacks its own species. In this way generally the smaller forms fall 

 a prey to the greater ; but sometimes an attack is made upon one 

 that, though weaker, is big enough to show fight, and can greatly 

 annoy with the powerful nippers the one that is feeding upon him ; 

 it is then the instinct is exhibited by the stronger in biting or 

 so wounding the claws of the weaker that they are thrown off, and 

 the foolish creature that has thrown away his only protection easily 

 becomes the prey of his stronger brother ; at least so infers Mr. 

 Gregson in the ' Zoologist' for 1857, from observations on Carcinus 

 Maenas in his own vivarium. 



These several observations in different species all exhibit a higher 

 amount of instinctive power than animals so low in the scale of 

 beings are supposed to enjoy ; and, moreover, it shows that in the 

 procuring of their food they are not simply the sea-scavengers, and 

 are no more to be considered as such than many fish. It is probable 

 that the smaller tribes of Crustacea come more under this appella- 

 tion, since the Talitri feed upon the offal that is found beneath the 

 festering weed thrown up by the sea, which they generally devour 

 where they find it ; but upon being disturbed they run off to their 

 holes in the sand, and, like careful purveyors, carry away with them 

 some food, that they may devour at their more convenient pleasure. 



The opossum-shrimp (My sis), which abounds in such numbers in 

 most estuaries, forming a band many feet wide, is a very greedy 

 feeder " seizing and eating every animal substance which the current 

 or tide carries along with it, and contending like vultures for the 

 possession of large masses. When confined together in a vessel of 

 sea-water they will even act the cannibal, killing and devouring one 

 another." (Mag. Nat. Hist. iv. 258). The unhallowed creatures ! 



(To be continued.) 



