CYLINDROCAPSA. 105 



than broad ; largely in pairs, enclosed in a hyaline sheath. 

 Oospores globose, with a wide hyaline envelope when 

 matured. 



Vegetative cells with sheath, 14-16 /* wide. 



Oospores, 23-25 //. 



Envelopes about 50 //. 



Widely distributed, New York to Florida and Westward. 



Plate XCI, figs. 1-17, from Pennsylvania specimens : fig. 1, 

 vegetative filament ; 2, 3, 4, filaments with cells in part 

 developed into oospores ; 5, 6, matured oospores ; 7, oospore 

 passing out of the envelope; 8, 9, antheridia; 10, 11, 12, 

 oospore dividing and developing young plants ; 13, 14, spore 

 divided into two, and another into four ; 15-17, a spore 

 developing. 



CYLINDROCAPSA AMOENA, Wolle. 



Filaments long and tenacious, clear and pearly in appear- 

 ance, particularly at the ends of the cells ; chlorophyl rather 

 light green ; contracts, forming a macrospore in each cell, 

 which rarely divides into two ; articulations not formed by 

 mere septae ; each cell has its own walls ; filaments not con- 

 tracted at joints. 



Diameter of filaments 7-12 //, often 2-3 feet long. Articu- 

 lations before division 2-3 times longer than broad. Ma- 

 crospores 7-10 f* by 13 /-*. Gelatinous tegument at maturity 

 about twice the diameter of the vegetative cells. 



A peculiar plant; has in appearance much in common 

 with Conferva amceua, Kg., and also with Ulothrix, but the 

 spore formation is more nearly related to Cylindrocapsa. 



Plate XCI, fig. 18, a vegetative filament indicating the 

 process of the cell division ; fig. 19, chlorophyl gathering in 

 center of cells ; fig. 20, the same more decidedly concen- 

 trated ; fig. 21, the condensed masses now develop into 

 macrozoospores ; fig. 22, more enlarged and showing signs 

 of active life by a vibrating motion, and then breaking 

 through the walls and escaping ; they are provided with two 

 cilia?, and live a short but active life ; coming to rest ( fig. 23 ), 

 the older break up into many small ciliated cells, micro- 

 zoogonidia. This may seem a somewhat abnormal proceed- 

 ing, nevertheless an actual observation ; possibly a result of 

 the drying up of the small pit. 



Have not rediscovered the plant since May, 1880. The 

 pools were examined year after year but without satisfactory 

 result. The plant may need farther study. 



