376 



NORTH AMERICAN DIPTERA 



Family Ccelopidae 



Coelopa, wing, head and front tibia and tarusus of ^. 



Flies of moderate size, living along the sea-shore. 



Thorax and abdomen flat, the former depressed, with bare, shining 

 mesopleura, the scntellnm flat above. Front with bristles; cheeks with 

 hairs and bristles, the face deeply concave; oral vibrissa absent or ex- 

 tremely weak; antennt^ short, pendulous, the second segment as large as 

 the first. Legs usually stout, with bristles and hairs, all the tibite with 

 dorsal preapical bristles; basal tarsal segment long; apical tarsal segment 

 broadened and with stout chiAvs. Wing venation complete, the second 

 basal and anal cells of equal length; auxiliary vein entire, the first 

 vein ending at the middle of the wing. 



The larvffi live in kelp washed up on the sea-shore and sometimes 

 occur in countless numl^ers. 



The genus Omoiiviia Coquillett, placed in this family by its 

 describer, belongs to the Pallopterida\ There is but one North American 

 genus, Calopa IMeigen. Aldrich* has recently reviewed the American 

 species. 



KEY TO AMERICAN SPECIES OF CCELOPA. 



1. First vein with a few hair.s on apical section above (California, Ore- 



gon) vanduzeei Cresson 



First vein bare 2 



2. Males 3 



Females o 



Revision 



CcElopa, Proc. U. S. N. M., Ixxvi, Article 11, pp. 1-6. 



