50 



Clarence J. Elmore 



1. Odontidium vulgare (Bory) Elmore. 



Diatoiiia vulgare Bory. Class. Diet., pi. 20, fig. ij. 1828. 



PI. 22, figs. 813-814. 



Cells broadly lanceolate to almost elliptical, sometimes slightly 

 produced at the apices; 40-60 /^ long, io-14/i wide; ribs 5-7 in 

 10 /A, striations finely granular, 14-16 in 10 /a; pseudoraphe indis- 

 tinct ; cells united in zigzag chains. 



In Wood River at Grand Island. 



Put-in Bay, Pond on Island in Lake Erie, Ohio. 



2. Odontidium elongatum (Ag.) Kuntze. Rev. Gen. Plant., Ill, 



2, p. 418. i8p8. 

 Diatonm elongatum Ag. Syst. Alg., p. 4. 1824. 

 PI. 2, figs. 57-61. 



Linear, Z7~7^ /* long, 4-5 /x wide, apices capitate ; costae delicate, 

 about 7 in 10 /x; striations fine, about 17 in 10 fx. 

 Devils Lake, N. Dak. ; Stockton, Cal. 



3. Odontidium hiemale (Ag.) Kittz. BacilL, p. 44, pi. ij, fig. 4. 



1844. 



Fragilaria hyemalis Ag. Syst. Alg., p. 7. 1824. 



PI. 2. figs. 62-65. 



Cells lanceolate or elliptical, sometimes with apices produced 

 (fig. 63), 15-50/* long, ribs 2.5-3 "'^ 10 M- striations 18-20 in 10 /x. 

 Var. luesodon, 0. niesodon Kiitz., is a form more nearly like the 

 specimens found. 



Bellevue. 



Fossil : Cherry Co. 



Chippewa Falls, Wis. 



4. Odontidium anceps (Ehr.) Elmore. 

 Diatoma anceps (Ehr.) Grun. 



PI. 22, fig. 815. 



Linear with apices rostrate or capitate, 20-50 fx, long, 5-7 /x wide ; 

 striations about 21 in 10 /i.; 6-14 heavy costae which are more or 

 less oblicjue ; cells rectangular in girdle view. 



In lake, Estes Park, Colo. 



