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University of California PuhUcations. [Entomology 



adjacent to it. The region in which the veins are thus weak- 

 ened, or nearly suppressed, is subject to so much variation 

 that it is impossible to give a diagram that will clearly show 

 the condition. 



As seen in Fig. 42, the venation is of a primitive and simple 

 sort, such as might be had by the suppression of the cross veins 

 of several of the Paleozoic types of venation, and in some cases 

 the suppression also of a few of the longitudinals. This wing 



FIG. 42. Diagram illustrating the venation of the Termitidse. 

 Dotted lines indicate alternative attachment of the independ- 

 ents. The number of these is somewhat variable. Cross veins 

 are omitted. 



shows clearly the instability of the basal attachment of the 

 independents, since they may be attached as branches to the 

 primary, or appear as a continuation of the posterior vein. 



Whatever differences of opinion there have been in homol- 

 ogizing these veins, they have all arisen from the idea that the 

 independent arises from the base like the other veins. There 

 are always five veins only — the primary, an anterior, a pos- 

 terior, and the two marginals. The large size of the wing-roots, 

 and the feebleness of the attachment of the wing to them, are 

 characteristic features of this group. 



EMBIID^. 



The small family Embiidae deserves a more careful study in 

 regard to the nature of the articulation of the wing. The 

 very anomalous position of these organs on the segment makes 



this particularly desirable. The 

 venation presents no difficulties 

 of interpretation, as will be seen 

 by the accompanying diagram 

 ( Fig. 43 ) . The feebleness of the 

 veins in the posterior part of 

 the wing allies these insects with 

 the white ants, with which they are commonly associated. 

 The general direction of the independent veins, however, 

 makes their venation verv distinct from that of the Termitidae, 



FIG 43. Venation of Embiidie. Dot- 

 ted lines indicate veins that may be 

 sometimes absent. 



