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Annals Entomological Society of America [Vol. XIII, 



with a pencil of hairs, no distinct sternopleurals, no preapicals, bristles 

 of middle tibiee more numerous, inside of front and hind tibiae and 

 plantar surface of their tarsi with dense dark-orange sole. 



Helcomyza mirabilis n. Lp. Male. 

 (Enlarged 3 diameters.) 



The first specimens of this remarkable species were dis- 

 covered in May, 1917, actively flying over the dry sands along 

 the seabeach near Ilwaco, Washington. Additional specimens 

 were taken on later visits to the same locality in July and 

 August of the same year, and in 1918, with the help of Anthony 

 Spuler and Miss Orilla E. Miner, enough specimens from the 

 same locality were captured to bring the collection up to eighty 

 individuals. The flies were difficult to catch, being alert and 

 quick to take to the wing, and with the sea breeze blowing, were 

 carried many feet along the sands before they would alight. 

 The males vary greatly in stature and vestiture, the largest 

 specimens being quite shaggy. This fine species is one of the 

 largest of the American Acalypterae. 



Actora ferruginea Walker, from Nova Scotia, is omitted from 

 the present discussion, as it clearly does not belong to the 

 Tetanoceridae. 



Dryomyza Fallen. 



Dryomyza convergens Walker, from Nova Scotia, is omitted 

 from the following table, since it almost certainly belongs else- 

 where. It has the thorax trivittate, the posterior crossvein 

 clouded, the arista downy, and the abdomen furnished with 

 short black bristles. 



