284 BUI.I.ETIN OF THE BUREAU OF FISHERIES. 



SPECIES OF POTAMOGETON AND THE ANIMALS FORAGING UPON THEM. 



To facilitate reference, a list is given of the species of Potamogeton, together with 

 the smaller animals which have appeared to be intimately associated with them. Other 

 forms of animal life were often found upon these plants, but none seemed to be so char- 

 acteristically on their own ground, so to speak, as the forms listed below. Those 

 animals are starred (*) which have been observed feeding on the living plant tissue. 



List of Potamogetons and Small Animal Forms Associated with Them.^ 



Plant. 



Animal. 



P. americanus Insecta, 



P. amplifolius. 



MoUusca. 

 . . Insecta . 



Mollusca . 

 P. perfoliatus Insecta. 



P. crispus Insecta . 



P. zosterifolius Insecta. 



P. obtusifolius Insecta. 



p. pectinatus Insecta. 



P. pectinatus 



(Gigantic form) 



p. Robbinsii . 



Crustacea . . 



Vermes . 



, Insecta. 



Diptera: 



Chironomidae (undetermined). 

 Lepidoptera: 



Pyralidje— 



* Nymphula sp. (Paraponyx). 

 Tricoptera: 



Leptoceridse — 



Two species. 

 Ancylus. 



Diptera: 



Ephydridae — 



* Hydrellia sp. 

 Chironomidce — 



* Chironomus sp. 



* Tanytarsus sp. 

 Tricoptera: 



Undetrmined. 

 Lepidoptcra: 

 Pyralidff — 



* Nymphula sp. (Paraponyx). 

 Ancylus. 



Diptera: 



ChironomidEE — 



* Tanytarsus sp. 

 Diptera: 



* Chironomidae (undetermined). 

 Lepidoptera: 

 PyraJidse — 



* Nymphula sp. (Hydrocampa). 

 Diptera: 



ChironomidEE — 



* Tanytarsus sp. 

 Lepidoptera: 



Pyralidae — 



* Nymphula sp. (Parai>onyx). 

 Tricoptera: 



Undetermined. 

 Diptera: 



Chironomidce — 



* Chironomous sp. 

 Cricotopus trifasciatus. 

 Tanytarsus flavellus. 



Diptera: 



Chironomidse — 



Tanytarsus flavellus 

 Cricopteris sp. 

 Tricoptera: 



HydroptilidEc (in autumn). 

 Coleoptera: 



Donaciine — 

 Donacia sp. 

 Diptera: 



Chironomidae — 



Chironomous sp. 

 Tanytarsus sp. 

 Amphipoda (very abundant). 

 Gammarus. 

 Hyallela. 

 Eucrangonyx. 



Nais (very abundant in autumn). 

 Diptere; 



Chironomidae — 



* Chironomus aberrans. 

 Tanytarsus sp. 



Tricoptera — 



Undetermined. 

 Lepidoptera: 



* Nymphula sp. (Paraponyx). 



a A Potaraogeton which came under casual observation only. P. Epihydrus, may be mentioned as an important addition to 

 the plants actually foraged upon by insect larvae. Several specimens of this species of Potamogeton, collected at Spencer Lake 

 in August, wer^ quite thickly dotted with caddis-fly larvae (Leptoceridae), which were feeding upon the fresh green leaves. 



