Q± THE FLORA OF NEBRASKA. 



Chaetophora cornu-damae (Roth) Ag. 1. c. 29. 



Rivularia cornu damae Roth 1. c. 332. 



( haetophora endiviaefolia Ag. Wolle Freshw. Alg. U. S. 117. 



Thallus light green or occasionally discolored, 1-8 cm long, explanate, lacin 

 iate or dichotomously branched; cells of the primary branches long- 

 cylindrical or subelliptical, slightly swollen in the middle, 10-15 /i broad, 

 2-5 times as long; cells of the ultimate branches 8-11 /i broad, equal to or 

 a little longer than the width, constricted at the articulations, the ter- 

 minal cell ending in a long, hyaline, articulate soft awn. 



Numerous varieties are described, most of which are only forms or stages in 

 the development of the mature plant. 



In clear water in many parts of the state. PL XVII., Fig. 1, a-g. 



6. STIOEOCIiOXIITM Kuetz. Phyc. Gener. 253. 1813. 



Thallus gelatinous, thin, indeterminate; brauches and branchlets scattered; 

 apical cell subulate, often ending in a long, hyaline awn; propagation by 

 4-ciliate macrozoogonidia; reproduction by the union of rnicrozoogonidia. 



Etymology: Greek oriyeog, sting, and k'/.ovwv, branch. 



Stigeocloninm tenne (Ag.) Rabh. PL Eur. Alg. III., 337. 1868. 

 Draparnaldia tenuis Ag. Syst., 57. 1821. 



Bright green, 1-40 mm. long, lubricous, sparsely branched; branches usually 

 simple, 9-15 >i in diam ; cell 1-5 times as long as diameter, slightly con- 

 stricted at the joints; branchlets short, nearly erect, subulate, apices 

 acute but not ending in an awn. 

 Very variable. Attached to sticks, roots, and stems in both running and 

 standing water. Very common. PL XVIII., Fig. 3. 



Stigeocloiiinm nairam (Dillw.) Kuetz. Sp. Alg., 354. 1849. 

 Conferva nana Dillw. Brit. Conferv. 71, t. 30. 1809. 



Cespitose, often 2-3 mm. high; filaments alternately branched; branches 

 abbreviated, somewhat attenuated upwards, ends obtuse, not piliferous; 

 cells equal to or a little shorter or longer than their diameter; 6-8 fi in 

 diam. 

 Forms a thin, slimy coating on sticks and stones in streams. Lincoln. 

 PL XVIII., Fig. 1. 



Stigeocloiiium fnstigiatiim Kuetz. 1. c. 356. 



Pale green, small, very much branched; branches radiately disposed, mucous; 

 upper branches alternate, fastigiate, moniliform, subpinnately approxi- 

 mate, erect, apices piliferous; filaments 10-15 fi in diam.; cells 1-3 times 

 as long as broad. 



Minden. PL XVIII. , Fig. 2. 



7. DRAPARNAUDIA Bory Ann. Mus. Hist. Nat. Par. XII., 399. 1808. 



Draparnaldia Agardh Syst. 57. 1824. 



Filaments articulate, much branched; the main stem comparatively thick, 

 composed of large, mostly hyaline cells, with a broad band containing a 

 few chlorophyll grains, always sterile, more or less densely furnished 

 with green, penicillate, fasciculate, opposite or alternate branches of 

 much smaller fertile cells; terminal cells of the branches empty, hyaline, 

 often elongated into a bristle. 



Etymology: dedicated to Draparnaud, a French botanist. 



The whole plant is involved in a soft mucous or gelatinous covering. 



