yo CONNECTICUT GEOL. AND N%\T. HIST. SURVEY. [Bull. 



Cryptomonas, Synura, Uroglena, Dinobryon. (See Bull. No. 2 

 of this Survey.) 



The only other family known to us to occur in our fresh 

 water is the following : 



FAMILY I. HYDRURACEvE. 



The plant consists of an attached colony, from two to twelve 

 inches long. The cells have each one chromatophore, lack a 

 cell wall, and are embedded in a large mass of jelly. Cells 

 brown at one end, colorless at the other; arranged in irregular, 

 longitudinal families ; at first globose, then elliptical. Division 

 at first in one, later in two directions. 



Asexual reproduction by uniciliated tetrahedral zoogonidia. 

 Two or four of them are produced from each cell of the 

 branches, and germinate at once. Resting spores have been 

 observed. 



Hydrurus Ag. Coextensive with the family. 



CLASS VII. RHODOPHYCE/E (FLORIDE^). 



Plants generally rosy red or purple, dark reddish-brown, or 

 blackish. Most closely related to salt-water Algae. Crust- 

 aceous, filamentous, variously branched. 



Asexual propagation by means of motionless spores. In the 

 sexual reproduction, which is wanting in some of the genera, 

 the female cell, called the carpogonium, is fertilized by a mass 

 of protoplasm, called spermatium, derived from a male cell. 

 The result of fertilization is called a cystocarp, and the method 

 of its formation determines the different groups of Rhodo- 

 phyceae. 



Sometimes the cystocarp is developed directly, and some- 

 times the fertilized carpogonium puts out growths, known as 

 obi a sterna-filaments, which conjugate with auxiliary cells, the 

 result being the cystocarp. The carpospores are always de- 

 veloped on a tuft of filaments which spring from the fertilized 

 cells and are called gonimoblasts. 



Of the four orders of this class, two are found in fresh 

 water. They are distinguished as follows : 



