22 The Ohio Journal of Science [Vol. XVI, No. 1, 



var. caeruleum nov, var. Cellulis vegetativis et sporis ut 

 in typo, sed membrana media sporarum caerulea. 



Vegetative cells and spores as in the type, except that the 

 median spore wall is steel blue. Type in Collection E. N. T. 

 No. 495. 



Zygnema stellinum (Aliiller) Agardh. 



The specimen distributed under the name Z. insigne (Hass.) 

 Kiitz. in the P. B.-A. No. 457, from Chestnut Hill, Mass. 

 (G. F. Moore), belongs to this species as shown by the scattered 

 mature spores. This species is common everywhere in central 

 Illinois. In the U. S. Natl. Herb, is a specimen from Baltimore 

 Co., Md., (J. D. Smith). In Amer. Alg. No. 157, a specimen 

 from St. Paul, Minn., (J. E. Tilden) shows both zygospores and 

 aplanospores. The aplanospores are cylindric ovoid in form, 

 occupying the entire cell 30-33jU x 40-88/x, median wall 

 scrobiculate. 



Zygnema cylindricum nov. sp. 



Cellulis vegetativis 28-33/x x 28-06^^; zygosporis incognitis; 

 aplanosporis cylindricis vel tumido-cylindricis, 30-33^ x 24-58//,, 

 sporangia complentibus ; membrana media brunnea scrbbiculata.- 



Vegetative cells 28-33// x 28-66/i; zygospores unknown; 

 aplanospores cylindric or tumid-cylindric, 30-33// x 24-58/t, 

 filling the sporangia, median wall brown, scrobiculate. Type 

 in Herb. E. N. T. No. 1164, 1177. 



This species is not uncommon in ponds, and pools through- 

 out central Illinois. It was at first classified as aplanosporic 

 material of Z. stellinum (Miiller) Agardh. On going over the 

 specimens in all my collections, however, it was found that in 

 no case were the filaments containing the aplanospores con- 

 nected with the filaments containing zygospores. This must 

 be the final test of the identity of the species, as it occurs in 

 some collections alone, sometimes associated only with fruiting 

 Zygnema pectinatum, and sometimes with Z. stellinum. 



Zygnema rhynchonema Hansg. 



In a collection of algae made at the Minnesota Seaside 

 Station, Vancouver Island, B. C, in 19(31, by Professor Tilden, 

 is a form which perhaps belongs here. The vegetative cells 

 are from 22-28/x in diameter, and 32-52// in length, while the 

 European specimens are described as lG-20// in diameter and 



