ORCHESTIA MEDITERRANEA. 33 



state, and articulates remotely from the apex ; it is so 

 short that it cannot reach to the extremity of the hand. 

 They are useless as organs of prehension, and appear too 

 feeble to hold, even if they could grasp, any object. 

 The three posterior pairs of legs are nearly equal in 

 their length, being strong and efficient organs for peram- 

 bulation, and fringed with stout hairs. The posterior 

 pair never have the fourth and fifth joints broader than 

 those upon the two preceding pairs of legs. 



This is a very active and vivacious creature. It hops, 

 when disturbed, to a considerable distance, taking a 

 direction always towards the sea. The female, from its 

 compressed form, and the fact that it can move the legs 

 only in a vertical plane, falls upon its sides and wriggles 

 along, until it intends to give a spring, when, having 

 managed to support itself upon its feet, with the pos- 

 terior portion of its body doubled up close beneath, it 

 boldly strikes out its tail with a force which sends it 

 several feet. By this means the caudal stylets and spines 

 are often broken or worn away. The male, by means of 

 the warty excrescence upon the last pair of legs, is en- 

 abled to walk without falling upon its side. This en- 

 largement of the middle joints of the last pair of legs is 

 not common to all the species of this genus, and in those 

 to which it belongs, it is developed only in the adult 

 state, and, according to Rathke, increases with age. It 

 is not a complete enlargement of the whole limb, but 

 one of breadth of a part only ; the leg existing in its 

 normal size as a ridge upon the inner surface. 



The female of O. mediterranea, according to Risso, car- 

 ries eggs many times during the year. The eggs of this 

 species are in an early stage of a deep purple colour, but 

 the young, when they first quit the pouch of the parent, 

 are of a bright orange. This species, particularly the 



