612 



ARTICULATA. 



THK SAND-HOPPKR MAGNIFIED. 



prosoiitini; notliiiii; l>ul llio .siiiuolli, cuiivox surlkco of liicir scaly armor to the onemv. This 

 Iniiiily also includes the Till-Bug, Armadillo pillularis. 



OKDKR 4. AMPHIPODA. 



This order consists of animals jiiostly of small size, none of them exceeding two inches in 



length. They usually live free in the water or burrow in sand ; a 

 few species are parasitic upon fishes. The Common Sand-]Iopper, 

 Talitrus locu.sta, -which may be met with in thousands upon the 

 sands of European shores, is a well-known example of this family. Al- 

 though its length is not much more than half an inch, it can leap 

 several inches into the air, and the facility with which it escapes 

 pursuit by burrowing into the soft wet sand is truly wonderful. 

 The Beach-Flea, T. quadrijidus, is found under stones and sea- 

 weed on our coasts. The European species, Gammarus pulex, 

 is found commonly in fresh water, and is scarcely inferior to its 

 marine relative in agility. The G. minus, one-third of an inch long, and called Fresh-water- 

 Shriinp, is a common American species, found under stones and pieces of wood. 



ORDER 5. LiEMOBIPODA. 



This curious little order includes only two families. The Cyamidce, or Whale-Lice, infest the 

 different species of cetaceous mammalia. They often live upon the whales 

 in such vast numbers that their victims may be recognized at a distance by 

 the whitish tint of their skin. The Whale-Louse, Cyamus ceti, is found on 

 the whales along our coasts. 



In the second family, the Cajjrellidce, all the proportions of the body are 

 reversed ; instead of being broad and flat, as in the preceding, it is long, slen- 

 der, and nearly cylindrical. The Caprella geometrica swims by alternate curv- 

 atures of the body; it is found among sea-weed and sponges, and walks like 

 the caterpillars called Measuring-Woryns. It is common on our coasts. 



ORDER 6. XYPHOSURA. 



This order consists only of a single genus, Limulus, the King-Crab, which, from the locality 



inhabited by the commonest species, is frequently termed 

 the Molucca Crab. It is among the largest of crustaceous 

 animals, sometimes measuring as much as two feet in 

 length. The body is composed of two divisions — an an- 

 terior, crescent-shaped piece, or carapace, and a posterior, 

 somewhat hexagonal piece, formed by the coalescence of the 

 abdominal segments. From the posterior extremity of this 

 second division of the body, projects a long, spine-like tail, 

 which exhibits no trace of segmentation. The upper sur- 

 face of the body is convex ; the lower surface, on the con- 

 trary, is concave in the middle, forming a hollow, in which 

 the feet are lodged. These curious animals appear to be 

 confined to the coasts of the East Indies and America. The 1 

 species common on our own shores, Limulns Polyphemus of | 

 Milne Edwards, is called Horse-Foot. It is often used for I 

 feeding hogs, and the shell is employed as a ladle. The French ; 

 colonists of the south called it Casserole-Fish from its re- i 

 semblance to a saucepan : the latter name is often given to j 

 it among us. The Indians used to point their arrows with S 

 THE KiNG-cBAB ou HORSE-FOOT. the sharp homy tail. ( 



TUK WHALE-LOUSE. 



