NEW SPECIES OF GREEN ALGAE 
Edgar Nelson Transeau 
In the course of my study of the periodicity of occurrence and 
reproduction of the algae of eastern lUinois during the past several 
years, a number of undescribed forms have appeared in the collections,, 
of which the following are now sufficiently well known to be described.. 
In accordance with the rules of the Vienna Congress a Latin as well 
as an English diagnosis is given in each case. Camera drawings from 
the type material are added together with notes on the relationship 
and occurrence of each of the new forms. A part of these species 
have been mentioned in two preliminary papers published by the 
writer. 1 
Zygnema Collinsianum nov. sp. 
Filamentis caespites laete virides efformans; cellulis vegetativis 
18-24 jjL latis, 1.5-4-plo longioribus; cellulis fructiferis in medio intror- 
sum inflatis; zygosporis globosis (26-40 diam.) vel oblongis (26-40 
X 30-47 ijl), maturitate caeruleis, mesosporio scrobiculis magnis ornato; 
aplanosporis cylindraceo-oblongis (18-24 X 40-76 /z), inter cellulis 
vegetativis sparsis, caeruleis et scrobiculatis. 
Filaments forming bright green masses; vegetative cells 18-24 M 
X 32-80^1, fertile cells inflated on the inner side near the middle; 
zygospores globose (26-40 /i in diam.) to oblong (26-40 ^ X 30-47 ju), 
blue at maturity, median spore wall marked by large pits; aplano- 
spores cylindrical-oblong, 18-24 ijl X 40-76 ,u, scattered among the 
vegetative cells, color and markings similar to the zygospores. 
This species is evidently closely related to Zygnema peliosponim 
Wittrock, but differs in the dimensions, form, and markings of the 
spores. It has been found in McCabe's pond and the railroad ditches 
between Briscoe and Casey, Illinois. In the material from McCabe's 
pond (Coll. No. 2271) the spores are formed in either of the conjugating 
filaments or in the tube between the two. Type in herb. E. N. T. 
Collections No. 1076, 1077. Plate XXV, figures 1-3. 
^ Transeau, E. N., The periodicity of Algae in Illinois. Trans. Amer. Microsc. 
Soc. 32: 31-40. 1913; Annotated List of the Algae of Eastern Illinois. Trans. 
Illinois Acad. Sci. 6: 69-89. 191 3. 
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