CHAPTER XL 



SOME OTHER CRUSTACEA. 



The opossum-shrimp and its allies Sessile-eyed Crustacea Structure 

 of Isopods The Amphipoda Characters and habits of sand- 

 hoppers Structure of Caprella The lower Crustacea Structure 

 and habits of acorn-shells and barnacles Crustacean parasites 

 Sea-spiders Their zoological interest. 



WHILE searching for shrimps and prawns, you are 

 certain sooner or later to encounter some little shrimp- 

 like creatures of singularly beautiful appearance. Far out 

 on the rocks, in clear pools floored with silver sand, you 

 will find them swimming with outspread eyes, and bodies of 

 crystal clearness. Turn to the shallower pools lined with 

 green weed and you will find similar forms, but here of the 

 same pale green as their surroundings. Again, if you push 

 aside the great blades of 

 Laminaria, you will see dart- 

 ing out from beneath them 

 in shoals the same little crea- 

 tures, but now of a deep 

 brown tint. This is My sis 

 flexuosa, sometimes called 

 chamceleon from its Protean 

 tints, and chain seleon-like in Flo . eo.-Opossum-shrimp (Mysis frx- 



its power of colour change. 



a -t, , t 



bwitt swimmers as they are, 

 they are easily caught, and, though difficult to keep in an 

 aquarium, they are well worth study. Collect a good 

 handful, and put them with plenty of clean water in a glass 

 jar. You will then have no difficulty in seeing that in 

 many respects they resemble shrimps and prawns very 



P 209 



uosa). Female specimen, showing brood 

 pouch between the posterior legs. 



