218 



LIFE, IN ITS INTERMEDIATE FORMS. 



The hiatus between these "Insects 'in Shells," as the 

 appellation Entomostraca signifies, and the true Crabs, is 

 occupied by an immense host of creatures still small, but 

 generally of a size above that of the Water-fleas. They 

 are commonly jointed throughout, without any carapace 

 or buckler on the fore parts of the body. The terrestrial 

 species are arranged here, of which the garden Armadillo, 

 or Woodlouse, already alluded to, is a familiar example. 

 They approach the nearest of the Crustacea to the true 

 Insects. Many of them have the faculty of rolling them- 

 selves more or less completely into a ball, like the hedge- 

 hog, and apparently for the same purpose, of opposing" a 

 passive resistance to annoyance. The Orders Isopoda and 

 Amphipoda, distinguished inter se principally by the struc- 

 ture of the limbs, are composed of these forms, which, 

 though they are of various interest, we are compelled sum- 

 marily to dismiss. 



' And thus we come to the most highly endowed repre- 

 sentatives of the Class, one of the most remarkable charac- 

 teristics of which is that their eyes, instead of being 

 imbedded in the head, or at most immoveably seated on 

 the surface, are placed at the tip of horny, jointed stalks, 

 which can be swayed about in various directions, greatly 

 increasing the animal's range of vision. Hence this Order 

 is called Podophthalma, or Stalk-eyed Crustacea. 



The strangest of these are the Glass-crabs (Phyllosoma), 

 animals of extraordinary beauty, found abundantly in the 

 tropical oceans, swimming at the surface far from land. 

 One species has been recently taken on the British shores. 

 They look like an oval plate of the purest glass, with a 

 broad tail and slender divergent limbs, so transparent and 



