3o6 



NORTH AMERICAN DIPTERA. 



forked at the end. The larvae of species of Notiphila have 

 been observed in the stems of water plants; those of Hy- 

 drellia in the sap of trees, in the parenchyma of the leaves 

 of Lemna, on Alisma, etc., those of Pclina, Ephv<ha y 

 Parydra, etc., in water, often salt or alkaline. 



The bristly spine of the second antennal joint is some- 

 times not easily discernible. I have included in both 

 sections some of the genera about which doubt may arise. 



Fig. 121. Ephydridae. 28, Beekeriella bispinosa, wing; 29,Parydra bituber- 

 citlata, head: 30, Mosillus, sp. wing; 31, Mosillus, sp. head; 32, Scatella sta<i- 

 fialis, wing; 33, Ilythea Jiavipes, wing; 34, llyihea flavipes, head; 35, Pelomyia 

 occidentalis, head; 30, Paralimna, sp. middle tibia; 37, Genus '. (Illinois). 



TABLE OF GENERA. 



i. Second basal and anal cells complete; auxiliary vein distinct 



throughout; third antennal joint spherical. . . Canace. 



Second basal cell confluent with discal cell; auxiliary vein coales- 



cent distally with first vein. ...... 2 



2. Antenna; small, inserted remotely in cavities, the arista atrophied; 



eyes pubescent; bristleless flies (26, 27t. . Lipochaeta. 

 Not such flies 2 



3. Second joint of antenna.' with a spinous bristle at upper distal cor- 



ner. ........... 4 



Second antennal joint without such bristle 16 



