66 EAMBLES OF A NATUEALIST. [Oh. IT. 



is, is a very tyrant over animals beautiful and delicate as 

 itself, and the pretty blue Porpitse are» the victims. But as 

 this was rare, so the glass-like crustacean, Alima hyalina, was 

 common in the net — ^lovely forms, whose carapace seemed 

 carved from the purest crystal, with an elegance of sculptur- 

 ing and sharpness of outline that could not be surpassed, — 

 perishable animals, but which, while they remained alive, 

 were active in the water. The only spots of colour in their 

 bodies were their two eyes, mounted on long, stalks, and 

 giving out a rich golden-green glow, which was positively 

 luminous. Almost equally transparent were the glass-crabs 

 (Phyllosoma), whose flat, leaf-like bodies and long branched 

 legs seemed as though made of fine plates of clear mica. 

 These nocturnal oceanic animals (for they never appear in 

 the net by day) are, however, very passive and quiet, and 

 seldom show any signs of life. It is not improbable that 

 they are larval forms of some possibly altogether different 

 beings. 



To find caddis-worms in the towing-net seemed remark- 

 able ; but small worm-like Crustacea (Cerapus), furnished 

 with large antennae, and living in tubes or cases, were not 

 unfrequently met with. These little creatures have usually 

 their head and foremost legs peeping out of their case, which 

 seems to be just large enough for the body ; but alarm it, 

 and it vanishes within, re-appearing immediately, head first, 

 at the other side, so that one can hardly be persuaded that 

 it has not two heads. Although some were minute, others 

 were of considerable size, and much larger than those 

 usually described. More than once, Hyalseas, and other 

 graceful Pteropods, were captured ; but one of these, pro- 

 bably the Hyalsea tridentata of Lamarck, presented appear- 

 ances such as I have nowhere seen described. When fij^st 



