ANIMAL LIFE OF THE SHORES 303 



into the water and was swimming for dear life to the 

 nearest shelter. Eventually it was secured and plunged 

 into a stone jar filled with alcohol, and the animal 

 could be heard delivering its postman's knocks against 

 the wall of its prison until it expired. The Stoma- 

 topoda include the well-known genus Squilla, those 

 elongate, almost crayfish-like Crustacea with huge 

 raptorial claws or chelipeds, that call to mind the 

 raptorial claws of the Mantidce amongst insects. The 

 function of these chelipeds is obvious : they are ad- 

 mirably adapted for grasping and holding the creatures 

 on which the Squilla feeds. But in Gonodactylus chir- 

 agra the chelipeds are not in the least adapted for 

 grasping purposes ; the basal joint is long and very 

 robust its apex carries a smaller dumb-bell shaped 

 joint, a small quadrangular joint intervening ; this 

 "dumb-bell" joint shuts down on the lower side of 

 the basal joint, and its apex bears the terminal joint, 

 which is so hinged that it shuts back on the upper 

 face of the " dumb-bell " joint. The terminal joint is 

 produced to form a spine, but its base forms a more 

 or less rounded and smooth knob the percussive 

 part of the whole apparatus. The animal rests near 

 the top of its burrow or hole with the chelipeds drawn 

 up in front of it in exactly the attitude which a Mantis 

 adopts when at rest ; on the approach of an intruder 

 the "dumb-bell" joint, with the terminal joint closely 

 applied to its upper surface, is violently pushed or 

 flung out by the action of the strong muscles inside 

 the robust basal joint. The action is as rapid as that 

 of a strong spring, and the force of the blow has to 

 be felt to be appreciated, and I am quite certain that 

 it is sufficient to stun any small fish or other Crustacea. 



