Nortlt American Species of Diaptomus. 205 



EXPLANATION OF PLATES. 



Plate XXI. 



Fig. 1. Diaptomus sicilis, fifth feet of male. X '280. 



Fig. 2. Fifth feet of female of same (minus one outer ramus). X 280. 



Fig. 3. Last thoracic segment and abdomen of female of same. X 140. 



Plate XXII. 



Fig. 1. Diaptomus piscina', fifth feet of male. 



Fig. 2. Fifth foot of female of same (Portage Slough specimen). X 280. 



Fig. 3. Last thoracic segment and abdomen of female of same. X 140. 



Fig. 4. Fifth foot of female (Yellowstone Park specimen). X 280. 



Plate XXIII. 



Fig. 1-5. Diaptomus sanguineus, second basal segment of right fifth foot 



of male. X 210. 

 FiG. 6-8. Terminal segments of right male antenna of same. X 210. 



Plate XXIV. 



Fig. 1, 2. Diaptomus sanguineus, first abdominal segment of female, seen 



from the side. X 110. 

 Fig. 3. Last thoracic and first abdominal segments of female of 



same. X 110. 

 FiG. 4. Fifth feet of male of same. X 210. 

 Fig. 5, G. Dorsal outline of female of same, showing hump. X 110. 



Plate XXV. 



Fig. 1, 2. Diaptomus sanguineus, fifth foot of female. X 240. 

 Fig. 3, 4. Right fifth foot of male of same. X 210. 

 Fig. 5. Fifth feet of male of same (variant). X 210. 



Plate XXVI. 



Fig. 1. Diaptomus shoshone, last thoracic segment and abdomen of 



female. X 80. 

 FiG. 2. Fifth foot of female of same. X 280. 

 FiG. 3. Abdomen of male of same. X 128. 



Plate XXVII. 



Fig. 1. Diaptomus lintoni, fifth feet of male. X 280. 



Fig. 2. Diaptomus pallidas, fifth foot of female. X 280. 



Fig. 3. Fifth feet of male of same. X 280. 



Fig. 4. Diaptoimis albuquerquensis, fifth feet of male. X 400. 



