168 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY 



[Bull. 



uloidea have lost E2 b}" atrophy, and in oroiips aboA^e the Tanyderidae 

 R2 has swung forward, forming E-1 + 2. K2 persists as a cross vein only 

 in Nemestrinidae and certain lower groups. In most lower Brachyc- 

 era R4 has become attached basally to R2+3, and the basal connection 

 may be lost entirely or represented by a spur. In all Brachycera in 

 which the free tip of R4 is retained, the connection with II5 is by a 

 supernumerary cross vein which is present in several Tanyderidae, 

 Tipulidae. and lower Brachycera. The terminologies of Comstock 

 and Needham, Shannon and Bromley, and Alexander in regard to 

 the radial field of the Asilidae are compared below. The system of 

 Alexander is followed in the tipuloid families of the present work. 



Inasmucli as the first volume of the Diptera of Connecticut in- 

 cludes no families beyond the Tipuloidea, a further discussion of the 

 wing venation is not necessary here. 



Tillyard's Modification 

 of Comstock-Needham 



Costa 

 Subcosta 

 Radius 

 Main stem 

 Sector 



First branch 

 Second branch 

 Third branch 

 Fourth branch 

 Media 

 First branch 

 Second branch 

 Third branch 

 Fourth branch 

 Cubitus 



First branch 



Second branch 

 First anal 

 Second anal 

 Humeral crossvein 

 Radio-medial crossvein 

 Intermedial crossvein 

 Medio-cubital crossvein 



Wing Veins 



Symbol 



c 



Sc 

 R 



Ri 

 Rs 

 Ro 



R3 

 R4 



R5 

 M 



Ml 

 Mo j 

 Ma I 

 M4 j 



Cu 

 Cu, 



CU2 



lA 

 2A 



hrn 

 rm 

 im 

 m-cu 



Loew 

 Costa 

 Auxiliary 



First longitudinal 



Second longitudinal 

 Third longitudinal 



Fourth longitudinal 



Fifth longitudinal 

 (distal J3art) 



Fifth longitudinal 

 (basal part) 



Sixth longitudinal 

 Axillary 



Humeral crossvein 

 Anterior crossvein 

 Posterior crossvein 

 Discoidal crossvein 



