THE LIFE OF DEVILS LAKE 101 



Among the plants all of the larger groups are represented, but 

 the flowering plants by practically only a single species. While 

 both fauna and flora have more fresh than salt water affinities, 

 there is one genus (Chaetoceros) and several species, which are 

 typically marine or brackish water forms. 



But while the fauna and flora are characteristically fresh wa- 

 ter, a comparison with those of fresh waters elsewhere reveals sev- 

 eral striking differences. Here, as in brackish water elsewhere, the 

 blue-green algae play a predominant role, while the diatoms and 

 desmids, which often form so important a part of the plancton, are 

 here, with the exception of the marine genus Chaetoceros, very ir- 

 regular in occurrence and comparatively small in number, altho of 

 the diatoms a large variety of species occur. Nodularia, which at 

 certain seasons is one of the most abundant plants in Devils Lake 

 is seldom met with in fresh water, while forms such as Aphanizome- 

 non, Aphanocapsa, Clathrocystis (Microcystis), Oseillatoria, and 

 Anabaena are either absent or of wholly minor importance. 



Of the Protozoa there are none of importance in the plancton, 

 and some forms, such as Ceratium, Synura and Dinobryon which 

 in other waters are often so abundant, appear to be wholly absent 

 here ; while the scarcity of shell-bearing rhizopods is noteworthy. 



The number of important species of rotifers and Crustacea is 

 comparatively few, there being but three of each. Among the for- 

 mer Brachionus satanicus and B. plicatilis spatiosus are new, while 

 Pedalia fennica has hitherto been reported from only a few locali- 

 ties. The rotifers which are usually most important in fresh water 

 are here either absent or of secondary importance. In their ex- 

 amination of a large number of lakes in the northwestern United 

 States Kemmerer et al. (1923), report Pedalia* from only one — 

 Medical Lake, Washington, which is so "distinctly alkaline" that 

 "no fish will live there for any period of time." 



The Crustacea are likewise signalized by the absence or rarity 

 of several animals, chiefly Cladocera (Daphnia, Bosmina, Leptodora, 

 etc.) which are characteristic of the plancton of fresh water lakes 

 in general. 



Of the nine orders of insects which Needham and Lloyd 

 (1916) give as common in inland waters four (Plecoptera, 

 Ephemerida, Neuroptera and Lepidoptera) have not been found in 

 the Devils Lake complex, while the Odonata and the Trichoptera are 

 represented by a single species each. 



Comparatively little work has yet been done on the alkaline 

 lakes of North America, so far as I am aware. Recently Huntsman 

 (1922), Willey (1923a) and Bailey (1922) have made a brief survey 

 of the Quill Lakes in central Saskatchewan, which shows a striking 



•Species not given. 



