Lake Maxinkuckee, Physical and Biological Survey 153 



50. COSMARIUM INTERMEDIUM Delpontc 



Found in some fine, fibrous material obtained at the ice-houses, 

 July 23, 1906, the material being gathered for the rich amount of 

 diatoms it contained. 



51. COSMARIUM SUBCRENATUM Hantzsch 



In a mass of tangled Cladophora collected along shore. 



52. MISCASTERIAS TRUNCATA SEMIRADIATA Naegeli 



A fine example obtained from the south end of Lost Lake, July 

 30, 1906, along with various diatoms, Pediastrum and Scenedesmus. 

 An unusually handsome desmid. 



53. DOCIDIUM VERRUCOSUM (Bailey) 



Apparently rare. Obtained only once, in a collection along 

 shore. 



54. CLOSTERIUM DIAN^E Ehrenberg 



Frequent in surface plankton hauls near shore, especially in the 

 region of Norris Inlet. 



55. SPIROGYRA CONDENSATA (Vaucher) 



Obtained in several hand collections along shore with Hydro- 

 dictyon, GEdogonium, Ulothrix, etc. Found in fruit in autumn. 



The genus Spirogyra is represented by numerous species in and 

 about the lake. Sterile filaments could be obtained abundantly at 

 all times of the year. Lost Lake, the Inlet region, Outlet Bay and 

 Culver Inlet on the Academy grounds were luxuriantly overgrown 

 with filamentous algae of all sorts, the growth in the Academy 

 grounds being especially luxuriant. Attempts were made to pro- 

 cure as many species as possible, but the difficulty of obtaining 

 fruiting specimens, especially with the pressure of other work and 

 interests, made it impossible to get a representative collection. The 

 task of making a complete or anything like a complete collection 

 of these algae is a great deal different from that of collecting float- 

 ing forms where such wholesale methods can be used as towing- 

 nets, etc., and would require the undivided attention of a specialist. 



In the economy of the lake, the coarse filamentous algae belong 

 rather with the pondweeds than with the plankton. They are prob- 

 ably eaten to some extent by herbivorous fishes, and certainly fur- 

 nish a good deal of turtle food, especially to the painted turtles, 

 which feed upon them to a considerable extent. 



There is, perhaps, a darker side to their case. One of the 

 dwellers of the lake region called them "malaria." We found that 

 Chironomus larva? eat them greedily and in all likelihood mosquito 



