356 
EXPLANATION OE PLATES. 
Tab. VI. 
Figs. 1, 2, 3. Daphnia pulex ; male and female, and 
variety. 
Tab. VII. 
Fig. 1. Daphnia Schcefferi , female. 
2. Do. young. 
3. Daphnia pulex ; variety longispina. 
4. Do. young. 
5. Daphnia reticulata , female. 
Tab. VIII. 
Daphnia Schcefferi, details. 
Eig. a. Head, principally to show the muscular system, a, n. Basal 
joint of large antenna, with its elevator and depressor muscles. 
b. Antennules. 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. 
Eig. b. Plead, principally to show the organs of digestion, b, c,fp , 
represent the same organs as in fig. a. d. Caecum, e. Stomach. 
g . Labrum. i. Heart. 
Eig. 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. h. Eourth do. i. Jltth do. p. Jaws. 
Tab. IX. 
Fig. 1. Moina hrachiata . Fig. 4. D. psittacea, young. 
2. Do. young. 
3. Daphnia psittacea. 
5. D. pulex, young. 
6. 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 show antennules. 
