16 A HISTORY OF RECENT CRUSTACEA 



shrimp will sometimes attract attention by making an 

 abrupt spring, after which it sinks softly into the moist 

 sand, from which its imitative colouring makes it barely 

 distinguishable. The stretches of sand on the shore, 

 which to unobservant or inexperienced eyes might seem 

 quite barren and deserted, are olten teeming with crusta- 

 cean life. The upper and driest zone will be riddled with 

 the burrows of the sand-hopper. Lower down several other 

 species of amphipods lie at a very small depth beneath the 

 surface. Little biting carnivorous isopods are there, and 

 occasionally others that are vegetarians. In some localities 

 Cumacea can be found, but never very far from the waves, 

 nor, when they are present, must it be expected that these 

 animals will make a striking feature in the landscape. 

 They are remarkably unobtrusive. Where rocks and 

 rock-pools and various kinds of seaweed abound, and 

 especially on sheltered coasts, a very large number of 

 species of amphipods and isopods may be obtained, these 

 being in most instances distinct from those found in the 

 sand. Here is to be seen Orchestia, the shore-hopper, a 

 near ally of the sand-hopper, Talitrus. Here are two of 

 the marine species of Gammarus, and examples of their 

 cousins Melita and Mcera^ all of which, when on land, slip 

 or wriggle along on their sides, and have in consequence 

 been irreverently spoken of as ' scuds.' Many other forms, 

 including some of the Caprellidas or skeleton-shrimps, can 

 be obtained by examining tufts of the finely branched sea- 

 weeds. At the lowest ebb of the spring tides, a day or 

 two after new moon or full moon, species may be obtained 

 which are rarely or never procurable higher up on the shore. 

 Several of the isopods, however, may be taken, indepen- 

 dently of the lowness of the tide, roaming among the 

 coarser weeds, and mimicking in various ways the colours 

 around them. The rocks which look least interesting, 

 having no vegetation except the short black crumbling 

 foliage of the Lichina pygmcea, supply the curious Cam- 

 pecopea hirsuta, an isopod easily to be confounded with the 

 leaves of the tiny plant which shelters it. Found among 

 cirripedes at low tide, however, it displays much brighter 



