1 64 Lake Maxinkuckee, Physical and Biological Survey 



13. GOMPHONEMA OLIVACEUM Ehrenb. 



14. NAVICULA REINHARDTII Giun. 



15. NAVICULA GASTRUM E. 



Naviculas of numerous undetermined species were present in 

 considerable abundance in the food of the mussels of the lakes. 



16. COCCONEIS PEDICULUS Ehrenb. 



One of the most abundant diatoms of the lake, frequently cover- 

 ing filaments of Cladophora and Spirogyra like an incrustation, 

 being closely attached to the filament by one side. Its habit and 

 appearance, suggesting a nit or louse attached to a hair, makes its 

 specific name highly appropriate. 



17. ASTERIONELLA sp. 



A species of Asterionella, probably formosa Hass, was exceed- 

 ingly abundant throughout the lake in the early spring and again 

 in late autumn after the water had cooled. It was found not 

 only near shore but it extended out to the center of the lake. On 

 some days it formed the main bulk of surface towings. The col- 

 onies of frustules arranged like the spokes of a wheel are striking 

 objects under the microscope. 



18. SYNEDRA RADIANS W. Sm. 



Rather common in gatherings along shore. 



19. SYNEDRA LONGISSIMA W. Sni. 

 20. SYNEDRA OBTUSA W. Sm. 



Besides being frequent in gatherings along shore, various spe- 

 cies of Synedra, some of them elongate, rather needle-like objects, 

 were frequent in mussel food. 



21. MELOSIRA VARIANS Ag. 



This is a very common diatom in the lake and is obtained both 

 in plankton hauls and in hand-gatherings along shore. According 

 to Apstein (Silsswasserplankton, p. 140) this species furnishes 

 food for various entomostraca (Chydorus, Daphnia, and Diap- 

 tomus) . The Melosiras are especially interesting as they form 

 the nearest approach among diatoms to the form of ordinary 

 filamentous algiB. 



22. MELOSIRA CRENULATA (E.) 



This, like Melosira varians, is a free-floating form, often taken 

 in towings and probably also used by entomostraca for food. 



