1 86 CHARLES T. BRUES. 



portioned to their size and exhibit a sharply defined color pattern of 

 hyaline and fuscous patches. They are normal wings in miniature. 



3. Eupelmus rhizophelus Ashm. (Chalcididae) (Fig. 7). 



One of the most remarkable modifications which I have ob- 

 served occurs in this insect. The wings which are much reduced 

 in size are suddenly bent upwards at a right angle near the 

 middle and project like two great spines at the apex of the meta- 

 thorax. The basal half is testaceous in color and flat, while the 

 raised extremities are black and somewhat curled with acute tips. 

 What their function may be I will not venture to suggest, but 

 their extraordinary form leaves little doubt that they are adapted 

 to some special use. 



4. Numerous Diptera, c. g. Phoridae (see Brues, '02) and the 

 genus Tennitoxenia, Wasmann (Fig. 10) show remarkable modi- 

 fications of the wings which evidently fulfill secondary functions 

 in these insects. 



THIRD CATEGORY. 



Although all wings falling into this group are necessarily with- 

 out salient characters, they show a considerable range of varia- 

 tion, which is not apparently correlated, however, with their sys- 

 tematic relationships. 



I. Pasimaclttis punctnlat'iis Hald. (Coleoptera) (Figs. 12, 13, 14). 

 In this carabid beetle the wings are larger than in Dictdus (see 

 below) and their larger size is accompanied by a more elaborate 

 form and 'much greater range of variation, as can be seen from 

 the accompanying figures. They have apparently not yet reached 

 the final minimum size and simple shape. By mounting the 

 wings of specimens which have been preserved in formalin, in 

 glycerine jelly, the tracheation of the wing can be readily made 

 out. A drawing made from such a preparation is shown in Fig. 

 14. The form of the single trachea was found to be almost 

 identical in several wings ; it is a simple tube and not dendriform 

 except for a few slender branches at the tip and at irregular in- 

 tervals near the middle of the wing where the diameter of the 

 trachea is greatest. The tsenidia are very distinct and the tube 

 is considerably coiled upon itself, being somewhat longer than 

 the wing. The development of the wing nervures has evidently 



