Vol. l.j Woodworth. — Wing Veins of Insects. 109 



second and following posteriors are bound together is also 

 characteristic of the neighboring families. A very similar 

 structure seen in the Diptera is not the same in origin. 



The homologies of the veins as worked out by Redtenbacher, 

 Brongniart, and Comstock are essentially alike. This is one 

 of the very few cases where it can be said that there is general 

 uniformity of opinion. 



HEMEKOBID^E. 



Each of the seven subfamilies constituting this group possesses 

 a venation that is quite distinct from the others; though the 

 definition of some subfamilies is difficult, because of the great 

 diversity of their contents. The venation is not so primitive 

 as in the Sialiche, as in every case there is evidence of some 

 particular specialization. 



A character seen in all members of the family, except in the 

 Coniopterygina^, is a tendency to excessive production of inde- 

 pendents. These are mostly short veins attached in such a 

 way as to appear as branches, or rather furcations, of the 

 longer veins. This tendency is carried to the extreme in cer- 

 tain Mj'^rmeleoninae. 



The tendency to coiJrdinate, or approximately coordinate, 

 cross veins is seen in Mantispina?, Hemerobinae, and Chryso- 

 pinse, always associated with a more or less evident reduction. 

 The tendency toward reduction extends to the longitudinal 

 veins in most cases, though in the Mantispina? these remain 

 very numerous. The smallest number of longitudinal veins 

 is seen in the Chrysopina?; in Coniopteryginse there is almost 

 an entire absence of cross veins. Only in these extreme reduc- 

 tions are the veins practically constant. Ordinarily, as in 

 most neuropterous venations, there is much variation, even in 

 the same species. 



There has been scarcely any difference of opinion as to the 

 homologies of the veins. The very evident relationship with 

 the preceding family prevents any very serious mistakes. In 

 smaller matters there is room for some difference of judgment, 

 but these need not be considered here. 



PANORPID.'E. 



The wings in this family exhibit a remarkable degree of 

 uniformity for an insect with numerous veins, contrasting 

 strongly with the nearest allies. The cross veins show a great 



