Myxophyceae 295 



538. Asterothrix creginii Wolle. Fresh-Water Algae U. S. 322. pi. 209. 



f. 22-25. 1887. De Toni. Syll. Algar. 5: 683. 1907. 

 Bennett. Plants of Rhode Island. 115. 1888. 



Plate XX. fig. 19, 20. 



Eilaments 2-4 mic. in diameter, short, pale blue-green; branches given 

 off at right angles, cross-like; trichomes often moniliform; transverse 

 walls usually evident. 



Rhode Island. Pocasset. (Bennett). Kansas. Norton. (Cregin). 



Genus GONIOTRICHUM Kuetzing. Phyc. Gen. 244. 1843. 



Colonies erect, filamentous, dichotomously or rarely unilaterally 

 branched; filaments at first unbranched, finally branched, by the repeated 

 division of cells at right angles; branches more or less regularly branched; 

 cells showing a central star-shaped chromatophore, a central pyr'enoid, and 

 an eccentric nucleus; cell walls diffluent into a gelatinous mucus which 

 forms a thick, gelatinous envelope surrounding each cell. 



I Colonies filamentous, solid, gelatinous, occasionally branched 



G. humphreyi 



II Filaments single or associated in rose-red bundles (colonies), usually 



thickened at the base, tapering above G. elegans 



I 



539. Goniotrichum humphreyi Collins in Collins, Holden and Setchell. 



Phyc. Bor.-Am. Fasc. 9. no. 421. 1898; The Algae of Jamaica. Proc. 

 Am. Acad. Arts Sci. 37: 251. 1901. De Toni. Syll. Algar. 5: 688. 

 1907. 



Colonies filamentous, solid, gelatinous, occasionally forking or dividing 

 into several branches, the terminal portion consisting of a single series of 

 cells, the older part containing numerous cells irregularly placed near the 

 surface of the filament; lateral branches abundant, simple, issuing nearly at 

 a right angle, composed of a single series of cells. 



West Indies. On woodwork of wreck. St. Ann's Bay. March 1893. 

 (Humphrey). 



540. Goniotrichum elegans (Chauvin) Zanardini. Notizie intorno alle Cel- 



lulari Marine delle Lagune e dei Litorali de Venezia. Atti R. 1st. 

 Ven. I. 6: 6g. 1847. De Toni. Syll. Algar. 5: 687. 1907. 

 Collins. The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 37: 251. 1901. 



Filaments 20 mic. in diameter, .3-6 mm. in length, single or associated 

 in rose-red bundles or colonies, usually thickened at the base, above taper- 

 ing, rarely unbranched, often somewhat dichotomously branched; cells 7-10 

 mic. in diameter, in one or many series, spherical or elliptical; cell con- 

 tents violet or reddish changing to green. 



