768 FRESH-WATER BIOLOGY 



53 (49) Terminal segment of right exopodite of male fifth feet of usual 



length, lateral spine terminal 54 



54 (55)^ Inner surface of left endopodite of male fifth foot rugose, terminal 



, , spines of endopodites 



' ^ of female fifth feet very 



long. 



Diaptomus stagnalis 

 Forbes 1882. 



A very large species 

 found in the Mississippi 

 Valley in the spring. 

 Length of female, 4 to 



4.5 mm. 



Length of male, 3.5 to 



4 mm. 



Fig. 1199. Diaptomus stagnalis. ^ , fifth foot of female. (After Forbes.) 

 B, fifth feet of male. (After Herrick. and Turner.) 



55 (54) In male, segments of right fifth foot short and broad, terminal hook 

 long and strongly curved, lateral spine long and straight; 

 in female, dorsal process on fifth cephalothoracic segment, 

 endopodites of fifth feet short and one-segmented. 



Diaptomus saltillinus Brewer 1898. 



Found in Nebraska. 



Length of female, 1.5 mm. 



Length of male, 1.25 mm. 



Fig. 1200. Diaptomus saltillinus. A. terminal segments of right antenna of male. X 193- 

 feet of same. X 126. C, fifth foot of female. X 19.3. D, dorsal process of same. 

 (Original.) 



