14 COLLINS AND HERVEY. 



Class MYXOPHYCEAE. 

 Family CHROOCOCCACEAE. 



Chroococcus Nageli. 



1. Cells 3-8 M diam., 1. C. membraninus. 



1. Cells 13-25 M diam. 2. C. turgidus. 



*1. C MEMBRANINUS (Menegh.) Nageli, 1849, p. 46; P. B.-A., 

 No. 2151; Pleurococcus membraninus Meneghini, 1842, p. 34, PL IV, 

 fig. 1 . In brackish pool near race course, Aug. ; in ditch in South 

 Shore marshes, Sept., Collins. In the material from the locality first 

 named the cells were dividing rapidly, and average smaller than in 

 P. B.-A., No. 1201, about like Wittrock, Nordstedt & Lagerheim, 

 No. 1538. Sometimes the division of the cells goes on so much 

 faster than the separation of families that a mass resembling a 

 Microcystis is formed. 



2. C. TURGIDUS (Kiitz.) Nageli, 1849, p. 46; Protococcus turgidus 

 Kiitzing, 1845-49, p. 5, PL VI, fig. 1. In gelatinous masses in brackish 

 pools, and in films on decaying algae near Flatts Bridge, April, CoUins. 



Synechocystis Sauvageau. 



* S. AQUATiLis Sauvageau, 1892a, p. CXVI. On rocks near Hungry 

 Bay, April; in cave, Agar's Island, Aug., Collins. 



Synechococcus Nageli. 



* S. aeruginosus Nageli, 1849, p. 56, PL I. E, fig. 1. Among other 

 algae in brackish pool near race-course, Aug., Collins. Cells about 

 14 X 7 ^c, which is rather small for this species. 



Chroothece Hansgirg. 



1. Cells seldom under 20 M diam. 1. C. Richteriana. 



1. Cells not over 3 ^l diam. 2. C. cr3T3tarum. 



1. C. Richteriana form'a marina Hansgirg, 1889, p. 5; P. B.-A., 

 No. 702. Farlow; rather common on shaded stone work and on sides 

 of caves, Collins. 



