FIG. 23. Brine-Shrimp (Branchipus), a primitive Crustacean found in 

 salterns in the south of England. The gills are fixed on the bases of 

 the swimming-legs. (From Lang's ' Comparative Anatomy.'} x 20. 



,, first antennae ; a 2 , the large second antennae ; va, unpaired eye ; /, liver ; 

 md, mandible ; ^sd, kidney ; A, heart ; oh, openings of heart ; />, male organ ; 

 *", gills. 



