Dactylococcopsis Smithii Chodat & Chodat 1925, p. 455 



PI. 105, Figs. 3, 4 



Colony ovate or broadly fusiform, containing 4-8-16 fusiform 

 cells which are nearly straight or slightly arcuate, sometimes paired 

 and lying end to end with one pole pointed and the other bluntly 

 rounded; cells 3.8/a in diameter, 11-15/t long. 



This species (listed as D. rhaphidioides Hansg. by Smith, 1920, 

 p. 47) was more frequently found in the region than any other 

 species of the genus. 



Common in the euplankton of lakes and ponds; also in rich 

 mixtures of algae in acid bogs and small lakes. Mich., Wis. 



CYANARCUS Pascher 1914, p. 351 

 Unicellular, solitary or gregarious in the mucilage of other algae, 

 or free-floating; cells curved rods, describing 1/2 to % of a circle, 

 sometimes lying in compact series with longitudinal axes parallel; 

 not tapering toward the apices, which are bluntly rounded; cell 

 contents blue-green, homogeneous. 



Cyanarcus hamiformis Pascher 1914, p. 351 

 PI. 103, Figs. 7, 8 



Characteristics as described for the genus; cells 0.5-0.75/a in 

 diameter, 3-4/* long; strongly curved, describing nearly a complete 

 circle, several cells lying together and parallel so as to form a short 

 cylinder. 



In a mixture of algae in a Sphagnum bog. Wis. 



APHANOTHECE NaegeH 1849, p. 59 

 Cells ovate, oblong or subcylindrical, densely but evenly arranged 

 and scattered throughout firm and copious mucilage, forming masses 

 which are often macroscopic and either amorphous or definite in 

 shape, free-floating or sedentary, sometimes subaerial; cell contents 

 either gray, olive, or bright blue-green, granular but not vacuolate; 

 cell sheaths indistinct and confluent with the homogeneous colonial 

 mucilage. 



This genus should be compared with Gloeothece which has been 

 differentiated on the basis of the definite, individual cell sheaths. 

 Because of the otherwise great similarity which exists between 

 species of these two genera, and because even the presence of cell 

 sheaths is sometimes demonstrable in Aphanothece, they have been 

 combined recently (Daily, 1942) and reassigned to the genus 



[465] 



