248 



THE ANATOMY OF INYERTEBRATED ANIMALS. 



and placed at the sides of the produced frontal rostrum, but 

 the antennae are very large, and constitute the principal loco- 



FiG. Qi.—Daphnia.—A, Side-view; the appendages not ficured except IP, the an- 

 tennules; IV, the mandibles ; and V, the maxillae. IIP, The place of attach- 

 ment of the antennse. £, Front view of head. 



cs, cephalostegite, or tbat part of the carapace which covers the head ; ms, omoste- 

 gite, or thoracic portion of the carapace ; c, heart ; st, cervical depression ; lb, 

 labrum ; P, compound eye ; IP, simple eye ; a;, the " shell-gland," which opens 

 behind the maxillae. 



motive organs. The posterior, or second, maxillse are obso- 

 lete. In £Jvad7ie, Polyphemus^ Sida, and other genera, sucker- 

 like organs of adhesion are situated on the anterior region 

 of the carapace. The eggs are developed in the cavity of the 

 carapace, and the embryos pass directly into the form of the 

 parent, except in Leptodora^ where they are, at first, Nauplius- 

 like. 



Limnetls and Estheria present a Da2:)hnia-\\ke carapace, 

 though more completely bivalve, combined with the numer- 

 ous segments of the body and the foliaceous appendages of 

 the typical Phyllopods (Fig. 65). 



Nebalm has a large carapace, provided with a movable 

 rostrum, like that of Sqidlla,, and arising entirely from the 

 head, which is remarkable for its very slight sternal flexure. 

 Tn this genus the eyes are large and pedunculated ; there 

 are well-developed antennules, antenntp, mandibles, and two 

 pairs of maxilUe, the anterior of which ends in a long palp. 



Branchipus, finally, develops no carapace either from 



