176 Trans. Acad. Sci. of St. Louis. 



EXPLANATIONS OP ILLUSTRATIONS. 



....Plate XXXVI. — Fig. 1. Diaptomus augustaensis, male, distal portion 

 of the geniculated antenna. — Fig. 2. Diaptomus augustaensis, male, 

 fifth foot. — Fig. 3. Diaptomus augustaensis, female, fifth foot. — Fig. 4. 

 Diaptomus augustaensis, female, posterior end of the abdomen. 



Plate XXXVII. — Daphnia hyalina, female, Stages in its life history. — 

 Fig. 1. First stage (from the brood-pouch), — Fig. 2. Second stage (from 

 the brood-pouch). — Fig. 3. Third stage (Free swimming). — Fig. 4. 

 Fourth stage. — Fig. 5. Fifth stage (just before it begins to bear eggs). — 

 Fig. 6. Sixth stage (four egg stage). — Fig. 7. Seventh stage (eight 

 egg stage, two eggs are out of focus). — Fig. 8. Eighth stage (twelve egg 

 stage, four eggs are out of focus). 



Plate XXXVIII. — Fig. 1. Bosmina reversaspina, n. sp., female. — Fig. 

 2. Eurycercus lamellatus, female. 



Issued December 31, 1910. 



