50 SPECIES OF AWJiE. 



35. EUGLENA. 



The question as to the animal or vegetal character of Euglena has 

 been debated. The present tendency is to consider it an alga, 

 although the evidence is rather negative than positive. For the 

 present purpose however, it seems best to leave it among the Infu- 

 soria, where the older investigators classed it. 



36. GONIUM. 



One species . . . . pectorale, 163 



37. STEPHANOSPHjERA. 



No forms yet found in this country. 



38. CHLAMYDOCOCCUS. 



a. Cells subglobose, brownish-red, sometimes green; variable, 



pluvialis, 164 



a. Cells globose, red; at first with a hyaline border; on the snow of 



high peaks, etc. .... . . . nivalis, 166 



39. CHLAMYDOMONAS. 



§ With a red pigment spot (a). , 



§ Without " " " (b). 



a. Ovate; length twice the width; pigment spot lateral, 



pluviusculus, 168 



b. Pale, whitish green; oblong-elliptical . hyalina, 168 



b. Bright light-green {c). 



c. Ovate or oval . . . iingens, 167 

 c. Spherical or nearly so . .... pluviale, 167 



40. pediastrum. 

 For full descriptions and figures of the species, see Wolle's "Des- 

 mids of the United States," from which the following classification is 

 compiled. 



§ Apices cuspidate, each cell with one cusp or bristle {a). 

 § " " " " " two " " " (c). 



§ Apices or angles, bidentate; small; cells often 4 . cuspidatum, 154 

 § Apices truncate; cells 4 in form of cross, 4-sided; small, tetras, 154 

 § Apices concave, undulate (d). 

 § Apices bilobed (if). 



a. Cells six, ovate or subfusiform, radiately connected; centre closed, 



simplex, 152 

 a. Cells six, 5 angled; centre open . . . Sturmii, 153 



a. Cells more than six (b). 



