CLADOCERA OF THE OKOBOJI REGION 
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Genus Camptocercus Baird 1843 
Camptocercus rectirostris Schoedler 1862. Abundant. Kettle holes. 
Camptocercus macrurus (O. F. Mueller) 1785. Rare. Drainage canal. 
Genus Kursia Dybowski and Grochowski 1894 
Kurda latissima (Kurz) 1874. Rare. Deep tows. 
Genus Acroperus Baird 1843 
Aero perns harpae (Baird) 1835. 
Acroperus angustatus Sars 1863. Abundant in kettle holes and surface 
tows of lake. Many intermediate forms are found. 
Genus Oxyurella Dybowski and Grochowski 1894 
Oxyurella tenuicaudia (Sors) 1862. Rare. Grassy kettle holes. 
Genus Leydigia Kurz 1874 
Leydigia quadrangularis (Eeydig) 1860. Abundant in smtall lakes, ket- 
tle holes and canal. 
Leydigia acanthocercoides (Fisher) 1854. Only a few specimens found 
in one kettle hole. 
Genus Alona Baird 1850 
Alona guttata Sars 1862. Common. Kettle holes and drainage canal. 
Alona guttata var. tuber culata Kurz. Found in one kettle hole. 
Alona affinis (Eeydig) 1860. Not common. Kettle holes. 
Alona quadrangularis (O. F. Mueller) 1785. Deep lake tow. 
Alona costata Sars 1862. Not common. Kettle holes. 
Alona rectangula Sars 1861. Common. Kettle holes. 
Alona intermedia Sars 1862. Not common. Smaller lakes. 
Genus Graptoleberis Sars 1863 
Graptoleberis testudinaria (Fisher) 1848. Not common. Surface tows 
of West Okoboji lake. , 
Genus Dunhevedia King 1853 
Dunhevedia setigera (Birge) 1877. Rare. Kettle holes. 
Genus Pleuroxus Baird 1843 
Pleuroxus procurvatus Birge 1878. Abundant. Kettle holes and sur- 
face tows of lake. 
Pleuroxus hasfatus Sars 1862. Rare. Kettle holes. 
Pleuroxus striatus Schoedler 1863. Not common. Kettle holes. 
Pleuroxus denticulatus Birge 1877. Very abundant. Everywhere. 
Genus Chydorus Eeach 1843 
Chydorus globosus Baird 1850. 
Chydorus sphaericus (O. F. Mueller) 1785. Abundant. Everywhere. 
Genus Alonella Sars 1862 
Alonella excisa (Fisher) 1854. Not common. Kettle holes. 
