THE CRUSTACEA 179 



burden, and by means of a pair of specially modified legs 

 carries the egg clusters until the young emerge ; in this 

 respect imitating the example of some of our fishes, the 

 SyngnathidcB (or " Pipe-fishes "), and some of the toads of 

 foreign lands. 



The male Nymphon can very frequently be found with 

 this precious burden. It is common among weeds in rock 

 pools in the upper parts of the littoral. 



There are other species on our shore closely allied e.g. 

 Pallene brevirostris, Phoxichilidium coccineum, Phoxichilm 

 spinosus, etc. All these are on about the same lines as the 

 above, but hardly so slender. These are found in similar 

 localities, but usually lower down in the littoral. 



Picnogonum littorale is, however, of very different build. 

 This one is stout limbed, and has a firm, hard shell, ap- 

 parently built up of blocks like a bit of mosaic work. It 

 is taken on shelly and stony ground low down on the 

 shore. It is also often attached to the bodies of cetaceans 

 (porpoise, dolphin, and whale), and is commonly con- 

 founded with the " Whale-louse," Cyamus an amphipod. 



Nymphon is shown of the natural size in Fig. 83. 



Fig- 83. Nymphon gracile. Male, Natural 



