136 Clarence J. Elmore 



8. Homoeocladia brebissonii (W. Sm.) Kuntze. Rev. Gen. 



Plant., Ill, p. 408. i8p8. 

 Nitcschia brebissonii W. Sm. Brit. Diat., I, p. 38, pi. 31, fig. 



266. 18 js. 

 PI. 18, fig. 710. 



Straight, arcuate, or sigmoid, 220-345 /* long, 12-15 yu, wide, 

 apices attenuate, sometimes capitate ; keel central with coarse dots, 

 4-5 in 10 fx.; striations 9-1 1 in 10 /x. 



Clear Lake, Grand Island, St. Paul, Snake River. 

 Fossil : Agate. 



9. Homoeocladia sigmoidea (Nitz.) Elmore. 



A'it::schia sigmoidea (Nitz.) W. Sm. Brit. Diat., I, p. 5<?, 



iS53- 

 Bacillaria sigmoidea Nitz. Bcitr., p. 104. iSiy. 



PI. 18, figs. 708-709. 



Linear or lanceolate with cuneate apices, 1 00-480 /x long; keel 

 nearly central with rounded dots, 4-8 in 10 /a; striations 24-30 in 

 10 |a; girdle face sigmoid, linear, or somewhat lanceolate with 

 truncate apices. 



In ponds, creeks, etc. : Grand Island, Lincoln, Orella. 

 New Concord, Ohio. 



10. Homoeocladia vermicularis (Kiitz.) Kuntze. Rev. Gen. 



Plant., Ill, p. 409. 1898. 

 Nitzschia vermicularis (Kiitz.) Hantz. in Rabenh. Alg., No. 



899- 



Synedra vermicularis Kiitz. Bacill., p. 6/, pi. 4, fig. 55. 1844. 



PI. 19, figs. 713-716. 



Linear or linear-lanceolate, straight or slightly sigmoid, apices 

 attenuate, sometimes capitate, 90-220 fi long, 4-1 1 /a wide ; keel 

 nearly central with slightly elongated dots, 6-10 in 10 /a; striations 

 very delicate, 30-34 in 10 /i.. 



In ditches, creeks, springs, etc., also fossil : Alma, Andrews, Arago, 

 Auburn, Blue Springs, Brock, Brownville, Clear Lake Crawford, Crete, 

 Culbertson, Fairbury, Glen Rock. Grand Island, Holbrook, Johnson, Julian, 

 Lincoln, Mason Cit3\ Minden, Nemaha City, New Helena, Norfolk, Omaha, 

 Orleans, Peru, Ruby, Rulo, Salem, Stanton, Stromsburg, Talmage, Valen- 

 tine, Weeping Water. 



