450 CYRTID^ 



]i Anal {or 6th longitudinal) vein. 

 i Axillary vein. 



Prsef urea = the common stem of the radial and cubital veins. 



Ambient vein = the con tin nation of the costal vein round the hindmargin of the 

 wing. 



Cross {or transverse) veins. 



w Humeral cross-vein, often absent in this family. 

 X Discal (or middle) cross-vein. 



y Lower (or small) cross-vein, sometimes distinctly present (vide fig. 259 G). 

 Anal cross-vein ==g^ = the lower branch of the postical vein. 



Cells. 



1 Costal (or mediastinal) cell. 



2 Subcostal cell. 



3 Marginal cell. 



4 Submarginal cell. 



A" Second submarginal (or cuhital) cell. 



5 First posterior (or subapical) cell. 



6 Discal cell. 



6'' Second posterior cell. 



6^ Third posterior cell. 



6" Fourth posterior cell. 



7 Postical (or 5th or last 2'>osterior) cell. 



8 Axillary cell. 



9" Upper (or 1st) basal cell. 



9"^ Second upper basal cell, peculiar to certain Cyrtidm (vide fig. 259 A). 

 9'' Second (or iniddle) basal cell. 

 9'' Anal (or 3rd basal, or loivest basal) cell. 

 10 Alula. 



Notes on the venation of the Cyrtidm. 



At first glance the system of venation in the British (and in fact most of the 

 European) species is difficult to recognise, but the study of other genera will help to 

 clear up most of the difficulties. 



Taking Lasia (fig. 259 A), which is nearest the Remestrinidce, the mediastinal, 

 subcostal, and radial veins are quite simple but the subcostal is unusually long ; the 

 cubital starts from a very short proefurca, and immediately sends down a thick 

 discal cross-vein to almost the base of the discal cell, after which it continues 

 parallel with the upper branch of the discal vein until close to the end of the discal 

 cell where it branches into a not very abnormal upturned cubital fork (of which the 

 branches are about equally upturned and both end before the wing-tip), and close 

 to the base of this cubital fork a supernumerary cross-vein occurs (not known in any 

 other family,* though obviously related to the contact between the cubital and 

 discal veins in Neviestrinidce (Ilermoneura, fig. 251) which represents the discal 

 cross-vein in that family) which ties the cubital vein to the upper branch of the 

 discal vein very near to (or a short distance after) the end of the discal cell. The 

 discal cell is very long (half the wing's length) and narrow being extended unusually 

 near to the wingmargin, and emits three veinlets, the upper one being in a 

 continuous line with the upper side of the discal cell, the second one sloping rather 

 strongly downwards, and the third one being recm-rent and closing the fourth 

 posterior cell. The postical vein is forked in almost the usual way, and the upper 

 branch just connects with the discal cell (leaving no small cross-vein) before the 

 middle of the latter, but then diverges again until it is caught by the third veinlet 

 from the discal cell, after which it bends down to the wingmargin ; the lower branch 

 of the postical vein slopes downwards and joins the anal vein considerably before 

 the wingmargin, thereby causing a closed anal cell. The upper basal cell is short 

 and broad, but according to the analogy in Nemestrinidce (tig. 251) the long narrow 



* Unless an adventitious cross-vein which occurs in some species of Exoprosopa, upon which Coquillett 

 proposed a genus Exoptata, may be of a similar character. 



