30 Salt Marshes and their Inhabitants. 



Corophium longicome is most commonly met with in the mud 

 of brackish ditches, flat sea-shores, and estuarine swamps, but 

 if the following passage from Quatrefages' " Rambles of a 

 Naturalist " may be trusted, it would appear to be an animal of 

 migratory habits. " Towards the end of April these little 

 crustaceans, termed by the fishermen of the coasts of Saintonge, 

 the Terms, arrive from the open sea in myriads. Guided by 

 their instinct, they come to wage an exterminating war against 

 the Annelids, which during the whole winter and early spring- 

 have multiplied undisturbed. As the tide rises these yoracious 

 hordes are seen moving about in all directions, beating the mud 

 with their long antenna, and pursuing Nerides and Arenicolas 

 to their deepest recesses. When once they discover one of these 

 animals, which are several hundred times larger than them- 

 selves, they combine to attack and devour it, and then resume 

 their, eager chase. This carnage never ceases till the Annelids 



have almost entirely disappeared Before the 



close of May the work is completed, and then the Corophium 

 turns upon the molluscs and fishes, which it attacks, whether 

 living or dead. Through the whole of the summer these crus- 

 taceans remain upon the coast, but towards' the end of October 

 they all disappear in one night, ready to return the following 

 year."* To this account we may add that in some places, far 

 removed from tidal influence, where we commonly find these 

 little crustaceans, the migration spoken of cannot possibly take 

 place. Probably the habits of the creature may vary according 

 to the circumstances in which it is placed. 



Another Amphipodousf crustacean, constantly met with in 

 the pools of salt marshes, is Gammarus locusta ; certainly not 

 an animal of beautiful or interesting aspect. Its dull brown or 

 greenish colour, its wriggling sideways motion when taken out 

 of the water, and its habit (shared by other members of the 

 family) of hanging together in couples, the large male carrying 

 the smaller female about beneath him, holding her by his 

 claws ; all these give the creature a certain repulsiveness. 

 Nevertheless, there are several very interesting points to be 

 observed respecting it. In the first place, this genus (Gam* 

 marvs) may bo said to bo tho type of the whole class of 

 Crustacea. In it the several parts of crustacean organization 

 are developed in tho most symmetrical and orderly way, and 

 may be separated and demonstrated, perhaps, more completely 



* Quatrefages' Rambles <>f a Naturalist on Ike Coasts of France, Spain, and 

 ;<ici!'i. roL ii., page 812. 



f The Edriopthalma, or sessile-eyed orastacea, are sub-divided mtoAmphipoda 



and Taopoda, the former being compressed laterally, and having feet adapted 



rimming and walking; the latter are flattened horizontally, and are 



lly formed I'm- running. Of the firsi named group, the common Sand- 



hoppn BM>y be taken as the type ; of the latter, the wood-louse or " Slater.'' 



