68 EREMOCH^TA 



Cells. 



1 Costal {or mediastinal) cell. 



2 Subcostal cell. • 



3 Marginal cell. 



4 Submarginal cell. 



4=^ Second submarginal {or cubital) cell {or cubital fork-cell). 



5 First posterior {or subapical) cell. 



6 Discal cell. 



6a Second posterior cell. 

 6'' Third posterior cell, 

 e*" Fourth posterior cell. 



7 Postical {or bth ■posterior) cell {or postical forlt-cell). 



8 Axillary cell. 



G" Upper {or \st) basal cell. 

 9'' Second {or middle) l:)asal cell. 

 d" Anal {or 3rd basal) cell. 

 10 Alula. 



Notes on the Venation of the STKATiOMYlDiE. 



The most characteristic points in the venation of this family lie in (1) the 

 praefurca and its origin ; (2) the cubital vein and its fork ; (3) the discal cell and the 

 veinlets issuing from it ; and (4) the postical vein and its fork. The last two of these 

 include the small cross-vein. 



(1) The Pk.efueca is the common base of the radial and cubital veins, and 

 originates from the subcostal vein. In the Stratiomi/idw (except in the Xi/lomt/ince) 

 it has the distinctive iieculiarity of originating opposite the base of the discal cell, 

 while in all the other families of the Brachycera (with the exception of some 

 C'l/rtidce and the concluding families) it originates very consideral^ly before the l>ase 

 of the discal cell. In many points the Xi/loitii/ince exhibit characters indicating an 

 affinity to the Lejitidce. 



(2) The Cubital Vein forks from the radial vein at the end of the i)nefurca, and 

 is the vein above the discal cell which is (except in the Sargince) connected to the 

 discal cell by the discal cross-vein ; in the Sargince this discal cross-vein connects 

 the discal cell with the prsfurca. The cubital vein is occasionally simple (figs. 84, 

 91), but is usually forked ; the fork may be very short and inconspicuous (fig. 79), or 

 may be long and conspicuous (fig. 82), but always originates after the end of the 

 discal cell, and (except in the Xylomjiimv) lioth Ijranclies of the fork end in the 

 costal vein before the tip of the wing. 



(3) The Discal Cell is always present, and is connected above by the Discal 

 Cross-vein with the cubital vein (except in the Sargince when it is connected with 

 the prasfurca), and usually below by the Small Cross-vein with the upper branch 

 of the postical vein, but sometimes the upper branch of the postical vein touclies the 

 discal cell (fig. 79) or even anastomoses for a more or less extent (rig. 77) with the 

 under side of the discal cell, in which case the small cross-vein is absent. The discal 

 cell is almost always pentagonal (except in the Xj/lomyince) and emits two or three 

 veinlets (irrespective of the upi)er branch of the i)0stical vein) towards the wing- 

 margin, and the number of the posterior cells varies from four to five, according to 

 tlie number of these veinlets ; two of these veinlets issue from what may be called 

 the end of the discal cell, and may occasionally ajjpear to issue by a common stem, 

 or on the other hand either of them may l)e more or less obsolete ; the tliird veinlet 

 may be entirely missing (fig. 77), or may be abortive (figs. 151, 152), or may be com- 

 plete, or may (in the Xylomyince) unite near the wingmargin with the upper branch 

 of the postical vein (fig. 82). 



(4) The Postical Vein is always a strong vein on the hind part of the wing 

 which invariably splits into two long branches. The upper_ branch is usually 

 connected with the discal cell by the small cross-vein, but sometimes it touches the 

 discal cell (in which case the small cross-vein is absent), and sometimes it forms for a 

 greater or less distance the lower margin of the discal cell. The lower branch almost 



