NO. 10 



CRUSTACEAN METAMORPHOSES — SNODGRASS 



15 



have taken on a leglike form ; their mesal margins are indented, and 

 each limb bears a conspicuous lobe, or flabellum, just proximal to an 

 apical point. The body is more lengthened behind the appendages and 



Fig. 3. — Branchiopoda. Branchinecta occidcntalis Dodds, developmental stages 

 (from Heath, 1924) and a thoracic limb of the adult. 

 A, newly hatched nauplius, length 0.4 mm. B, second instar. C, third instar. 

 D, fifth instar. E, eighth instar, 2.9 mm. F, sixth left thoracic limb of adult 

 male, with six endites {1-6) and a movable terminal lobe (Dactpd). G, head of 

 adult male, anterior, with large second antennae (^Ant). 



shows lines of further segmentation. After two more moults, the 

 larva in the fifth instar (D) reaches an average length of 1.6 mm. 

 The second antennae are relatively much shortened, but the legs have 



