360 EXPLANATION OF PLATES. 



TAB. XXI. 

 Fig. 1 . Cythere inopmata. 



a. Ventral view. b. Superior antenna, c. Inferior do. d. First 

 pair of legs. e. Last pair of do. 



2. C. quadridentata. Fig. 8. C. aurantia. 



3. C. convexa. 9. C. impressa. 



4, 4. C. nigrescens. 10, 100,11. C. varin- 



5, 5 a. C. acuta. bilis. 



6, 6. C, angmtata. 12, 1'2 a. C.favida. 



7. C. peUucida. 



TAB. XXII. 



Fig. 1 . Cypridina Mac Andrei. 



a. Animal, with the shell removed. /;. Natatory feet. c. Second 

 pair of antennae, d, d. Second pair of jaws. e. First pair of 

 antennae, f. Oviferous foot. g. Abdomen. 



TAB. XXIII. 

 Fig. 1 . Cypridina Brenda. 



n. Eye. b. Natatory foot. c,c. Second pair of antennae, d. Second 

 pair of jaws. e. First pair of antennae. /. Oviferous foot. 

 g. Branchial plate of first pair of jaws. 



TAB. XXIV. 



Cyclops quadricornis. 

 Fig. 1. Male. Fig. 6. Ovum. 



2. Female. 7. Young, just born. 



3. Var. , elongatus. 8. Do. 8 days old. 



4. Var. b. 9. Do. 15 days old. 



5. Var. c. 10. Do. 17 days old. 



a. Anteuuule. b. Mandible, c. First pair of foot-jaws, d, e. Se- 

 cond pair of foot-jaws, (d. Internal division, e. External 

 do.) /. First pair of thoracic feet. g. Fifth pair of feet ; 

 fulcra, or "supports." 



