TJie Diatoms of Nebraska 163 



Obtusae 137 



Odontidium Kiitz 45 



anceps (Ehr.) Elmore, pi. 22, fig. 815 50 



elongatum (Ag.) Kuntze, pi. 2, figs. 57-61 50 



harrisonii W. Sm 53 



hiemale (Ag.) Kiintz., pi. 2, figs. 62-65 50 



mesodon Kiitz., 50 



mutabile W. Sm 50 



vulgare (Bory) Elmore, pi. 22, figs. 813, 814 -50 



Odontodiscus Ehr 41 



Okedenia Eulenst 124 



Onkosphenia Ehr 48 



Opephora Petif. 47 



pacifica (Grun.) Petit 47 



Oscillaria Schrank 130 



Palpebrales 83 



Peronia Breb. and Arn 47 



erinacea Breb. and Arn 48 



Perstriatae 83 



Pinnulariae 63 



Pinmilaria aestuarii (Breb.) CI 66 



borealis Ehr -. ^ 



decurrens Ehr 68 



dicephala Ehr 80 



digit o-radiata Greg : yy 



gibba Ehr 68 



integra W. Sm 82 



major Rabenh 64 



peregrina Ehr y^) 



placcntula Ehr 79 



nobilis Ehr 64 



rangoonensis Grun 67 



subcapitata Greg '. . 69 



thermes Ehr 70 



Plcurosigma W. Sm 104 



dclicatulum W. Sm 105 



kiitcingii Grun 105 



scalproides Rabenh 106 



spencerii W. Sm 106 



Pritchardia Rabenh 130 



Radiosae 71 



Rhoicosphenia Grun 114 



curvata (Kiitz.) Grun., pi. 15, figs. 577-581 114 



Scalprurn Corda 104 



Sceptroneis Ehr 47 



