356 EXPLANATION OF PLATES. 



Tab. VI. 



Figs. 1, 2, 3. Dajphiia pulex ; male and female, and 

 variety. 



Tab. VII. 



Fig. 1. Baphnia Schcejferi, female. 



2. Do. young. 



3. Daphuia pulcv ; variety longispina. 



4. Do. young. 



5. Daphnia reticulata, female. 



Tab. VIII. 

 Daphnia Schcefferi, details. 



Fig. a. Head, principally to show the muscular system, a, n. Basal 

 joint of large auteima, with its elevator and depressor muscles. 

 b. Autenuules. c. Eye, with its rotatory muscles, optic nerve, 

 and brain, e, k. Muscles attaching the body of the animal to the 

 carapace, f. Mandible, with its muscles, g. Muscle of the 

 labrum. p. Jaws. 



Fig. B. Head, principally to show the organs of digestion, h, c,f,p, 

 represent the same organs as in fig. a. d. Caicum. e. Stomach. 

 (/. Labrum. /. Heart. 



Fig. c. Labrum, with a, b, c, its elevator and depressor muscles. 

 D. Mandible, e. One of the first pair of legs. f. Second do. 

 G. Third do. u. Fourth do. i. Fifth do. p. Jaws. 



Tab. IX. 



Fig. 1. Moina brachiata. Fig. 4. D. psittacea, yowwg, 



2. Do. young. 5. D.pidex, young. 



3. Daphnia psittacea. 0. D. rotunda, young. 



Tab. X. 



Fig. 1. Daphnia vetula. 



a. Head magnified to show antennules. 



2. D. mucronata ; var. obtuse rostrata. 



3. D. mucronata ; var. acute rostrata. 



4. D. rotunda. 



a. Head magnified to sJiow antennules. 



