288 FRESH-WATER ALG.E OF THE UNITED STATES. 



cysts intercalated, paler ; spores numerous seriate, ellipsoid, 

 golden tawny, with a rather thick membrane. 



Diameter of cells, 3.54^; heterocysts and spores, 7-8 jj. 



Syn. Sphaerozyga Thwaitesii, Harv. ; Sphaer. variabitis, Kg. ; 

 Trichormus rectus, Ealfs ; Anahcena licheniformis, Hass. ; 

 Trichormus Thwaitesii, Ealfs. 

 In ditches and smaller ponds. 



Plate CXCVIII, figs. 29-32, four short filaments ; spores 

 variable in size as they approach maturity. 



ANAB.ENA STAGNALIS, Kg. 



Forming a gelatinous stratum, dilute aeruginous, some- 

 times turning to yellowish ; trichomes more or less flexu- 

 ously curved, usually occurring in clusters ; joints globose 

 and elliptic intermixed, closely connected, finely granular ; 

 heterocysts few, elliptic, fully tAvice the diameter of the 

 vegetative cells ; spores spherical, as large as the heterocysts. 



Diameter of vegetative cells, 3-4 yw. 

 Margins of pools, ponds, etc. 



ANAB^NA OSCILLARIOIDES, Bory. 



Forming a bluish stratum ; trichomes elongated flexuous, 

 joints subquadrate, distinct; heterocysts barrel-shaped or 

 elliptic ; spores oval, catenate, somewhat larger than the 

 vegetative cells. Intermingled occur filaments which have 

 the appearance of Oscillaria. 



Diameter of cells, 4-5 /*. 



Syn. ftphaerozyga oscillarioides, Kg.; Trichormus oscillarioides, 

 Ealfs ; A. gelatinosa, Wood. 



In brackish ditches, Southern New Jersey. The latter, 

 A. gelatinosa, evidently an imperfectly developed plant. 



Plate CXCVIII, figs. 39, 40, filaments in different stages 

 of growth. 



AN AB JEN A CUPRESSAPHILA, Wolle. 



Forming a gelatinous, submembranaceous, deep aerngi- 

 n'ous, stratum on cedar trees. Trichomes nioniliform, en- 

 closed in a delicate sheath, slightly curved, or nearly 

 straight, more or less parallel, light aeruginous ; vegetative 

 cells about half as long as wide, granular, sometimes sep- 

 arated ; heterocysts intercalated, brownish yellow, com- 

 pressed globose, homogeneous. 



Diameter of filaments, 7-8 yw. 



