The Two-winged Flies 



3U 



which have a sort of sieve-like skin. In both cases the pupa breathes the 

 oxygen which is mixed with water and is thus not ,. ,^ 



compelled, as are the mosquito pupa;, to come to the .J^s. ■ ■ ■ 



surface for air. The larvx' of the genus Ceratopogon 

 and its allies, which include the fiercely biting and 

 blood-sucking little punkies (Fig. 422), so irritating 

 to the fisherman and hunter in the north woods, 



Fig. 420. Fig. 421. 



Fig. 420. — Larva of a midge, Chironomus sp. CFrom life: natural length i inch.) 

 Fig. 421. — Pupa of midge, Chironomus sp. (From life; natural length J inch.) 



live, according to Comstock, "under the bark of decaying branches, under 

 fallen leaves, and in sap flowing from wounded trees. " 



Running and half flying about over the spray- wet rocks and on the surface 

 of the smaller tide-pools between tide-lines on the ocean shore near Mon- 





Fig. 422. Fig. 423. 



Fig. 422. — Mouth-parts of a female "punkie," Ceratopogon sp. lb., labrum; md., 



mandible; m.v., maxilla; m.v./., maxillary lobe; mjc.^., maxillary palpus; /»., labium; 



p.g., paraglossa; hyp., hypolhorax. 

 Fig. 423. — The tide-rock fly, Erclmoplcra browni. (Xatural length J inch.) 



terey, California, may be seen in the winter months many small, long-legged, 

 spider-like flies (Fig. 423) whose wings are reduced to mere oar-like veinless 

 rudiments. The larva; and pupa; live submerged in the salt water of the 

 outer and most exposed tide-pools, where the ocean water is held in shallow 

 depressions in the rocks, and is changed many times daily by the dashing 

 of the waves. \\'here the flies go when the tide is in and these rocks are 



