248 



THE ANATOMY OF INVERTEBRATED ANIMALS. 



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

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



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

 tennules; IV', the maudibles ; and V, the maxillae. Ill', The place of attach- 

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



cs, cephalostfgite, or toat part of the carapace which covers the head ; ms. omoste- 

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

 labrum ; 1', compound eye; 11', simple e>e ; a; the •"shell-gland," which opens 

 behind the maxillae. 



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

 lete. In I^Jvachie, 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. 



Limnetis and Esther ia present a Daphnia-like carapace, 

 though more completely bivalve, combined with the numer- 

 ous segments of the body and the Ibliaceous appendages of 

 the typical Phyllopods (Fig. 65). 



Neballa has a large carapace, provided with a movable 

 rostrum, like that of Squilla^ and arising entirely from the 

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

 In this genus the eyes are large and pedunculated ; there 

 are well developed antennules, antenna^, mandibles, and two 

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



Branchipxis^ finally, develops no carapace either from 



