44 PREDACIOUS AND PARASITIC ENEMIES OF APHIDES. 



I had hoped, when first examining these delicate changes, to 

 find evidence of a definite nature as to the coincidence in the 

 embryological growth of the two genera ; but although the simi- 

 larities are many and well marked, and are considered by Dr. 

 Packard to be conclusive, I cannot altogether accept his view, on 

 account of the change in position of the embryo, and I conclude 

 that the evidence afforded by embryological examination is too 

 doubtful to have much weight in the question of the relationship 

 of the sub-orders of the Neuroptera. But although this pomt is 

 left in doubt, the general habits and structure of the larvge, the 

 wing venation of the imagines, and the failure to find any really 

 weighty indications of a relationship in any genera with either the 

 Orthoptera on the one hand or the Coleoptera on the other, lead 

 me to conclude that no sufficient ground has been shown for dis- 

 turbing the Linnean arrangement of the order. 



EXPLANATION OF PLATES I. AND II. 



Plate I. 



Fig. 1. — Imago of Myrmeleoti, for'micarius. 



,, 2. — Imago of Calepteryx virgo. 



,, 3. — Principal nervures of wing in Calepteryx. 



,, 4. — Same in wing of Sialis lutaria. 



In these figures the lettering refers to the similar nervures 

 in each, a being the cubital point ; hb the anti-cubital trans- 

 verse nervures ; dd and e the radii ; c is the costal nervure ; 

 g in Fig. 4 exhibits well the progress of the obliteration of a 

 nervure, being often scarcely traceable through greater part 

 of its length. 



,, 5. — Wing venation of Agrion puella. This species exhibits an 

 arrangement of the nervures in the main corresponding with 

 that of the Odonata generally ; but towards the lower edge 

 the shape of the cellules and the short, sparse hairs show the 

 relationship to the lacewings, while the structure towards the 

 apex recalls distinctly the venation of the Trichoptera. 



,, 6. — Labium of Gryllus dumesticus, exhibiting the deep central 

 division. It should be observed that this organ is of a fleshy 

 character. The drawing is made from the upper or dorsal 

 surface. 



Plate II. 

 Fig. 1. — The labium and pal[)i of Hemerobius, seen from beneath. 

 ,, 2. — The same organs in tSialis lutaria, seen from above. 



