6 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



We have adopted the plan used in the Bulletin on the Pro- 

 tozoa of indicating by a * in the analytical keys the genera that 

 have been found in our waters. In a number of cases the 

 genera thus indicated have not yet been found by ourselves, 

 although known to occur in Connecticut. We have given de- 

 scriptions of all the genera likely to be found in this vicinity, 

 whether already known to occur in Connecticut or not. 



So far as possible we have determined the species of the 

 forms studied and figured. While there is considerable varia- 

 tion among the individuals of the same species of Alg3e, it is 

 less than among the Protozoa, and it is less difficult to deter- 

 mine species. In most cases there has been little difficulty 

 in affixing specific as well as generic names to the Algae found. 

 In some genera the determination of species is nearly im- 

 possible without the whole life history of the specimen under 

 consideration. In the genus Spirogyra, for instance, the 

 species are determined with certainty only when one has the 

 zygospores for study. The ordinary student of Algae is seldom 

 so fortunate as to have the zygospores, and must in these 

 cases make his determination from other characters. We have, 

 therefore, in these cases determined the species as well as 

 possible from the general structure of the plant, thinking this 

 to be more practical than to rely upon the more rarely seen 

 zygospores. 



The figures have all been drawn from nature, and all from 

 specimens found by ourselves in our waters. A majority of 

 them have come from the immediate vicinity of Middletown. 

 Collections have been made from other parts of the state, but 

 these other localities have not yet yielded many forms not 

 represented in this immediate vicinity. The Algae have not 

 been to a very large extent obtained from city reservoirs, since 

 these localities are not very profuse in this kind of life. Road- 

 side pools, ditches by railroads, swamps, stagnant pools, etc., 

 have been more prolific sources of Algae. 



The late Isaac Holden made during his life large collec- 

 tions of Algae in the state. The largest number of the types 

 that he collected were marine, but he also made quite exten- 

 sive collections of the fresh-water forms. A list of the species 

 identified by him in this state has been recently published by 



