298 



THE CRUSTACEA 



larval stages, more especially among Arctic, abyssal, and freshwater 

 forms. A specially interesting case is that of Palaemonetes varians, 



FIG. 1T4. 



Later stages of Leucifer. A, younger Scluzopod -stage. B, later Schizopod-stage (less- 

 magnified). C, Mastigopus-stage. a', antennule ; n", antenna ; abi-abs, pleopods ; abg, 

 uropods ; c, carapace ; dr, antennal gland ; en, flagellum, ex, scale, of antenna ; md, mandible ; 

 inf, mf", first and second maxillipeds ; inif, maxillula ; mx", maxilla ; o, paired eye ; oc, nauplius- 

 eye ; ol, labrum ; r, rostrum ; 1-6, abdominal somites. (After Brooks, from Korschelt and 

 Heider's Embryology.) 



