ANNULOSA : CRUSTACEA. 



229 



or "foot-jaws," and a bifid lower lip, or "metastoma." The 

 five remaining segments of the thorax carry the five pairs of 

 ambulatory legs, of which the first (fig. 74, i) constitute the 

 great claws, or " chelae ; " the next two pairs (2 and 3) are also 



¥ig, 74. — Macnira. Common Lobster {Hofnarus vuigaris). i. First pair of legs, 

 consntuting the great chels or nipping-claws ; 2. Second pair of legs, also chelate ; 

 3. Third pair of Tegs, also chelate ; 4 and 5. "List two pairs of ambulatory legs, with 

 simply pomted extremities ; a Antennules ; ga Great antenneb ; ca Carapace. 



chelate, though much smaller ; and the last two pairs are ter- 

 minated by simply pointed extremities. The segments of the 

 abdomen carry each a pair of natatory limbs, or " swimmerets," 

 the last pair being greatly expanded, and constituting, with the 



