228 



ME. E. M'LACHLAN ON A SYSTEMATIC 



"With regard to the sequence and affinities of the genera, I be- 

 lieve it to be impossible to rely upon any special characters in 

 the imago alone, and consider that no thoroughly stable arrange- 

 ment can be arrived at until a knowledge of the earlier stages 

 and general habits can be acquired. One should rely more upon 

 facies in the present crude state of the family as a guide to af- 

 finities. An arrangement based upon special characters would 

 tend to widely separate forms which are evidently closely allied 

 one to the other, and would place in juxtaposition those with 

 little relationship. It seems probable that even the obvious 

 character of the entire or divided eyes will eventually be found 

 insufficient to maintain the existence of two divisions, however 

 useful the character may appear at the present time. 



I have given no characters derived from an examination of the 

 parts of the mouth, such examination being almost impossible in 

 dry examples. 



This appears to be the best place for a discussion of the affini- 

 ties of the anomalous genus Stilbopteryx, Newman (Azesia, Le- 

 febvre) . Lefebvre placed it unhesitatingly in the Ascalaphidce, and 

 succeeding writers have pretty generally followed him. It should 

 be remarked, however, that the most obvious character, the very 

 short antennae, was not observed by him, in consequence of these 

 organs being wanting in his type ; in his figure he supplied ideal 

 long antennas, as is usual in the family. Hagen, in I860 

 (Stett. Ent. Zeit. p. 372), transferred the genus to the Myrme- 

 leonidce, stating that he did so in consequence (especially) of the 

 character of the reticulation of the poststigmatical area, which is 

 made up of numerous small oblong cellules, whereas in the -4s- 

 calaphidce these cellules are ordinarily many-angled. I fail to 

 appreciate this character to the extent that my friend Dr. Hagen 

 does, because in some Ascalaphidce (e. g. Orphne) there is a de- 

 cided tendency to this obloug building of the cellules, and, on 

 the other hand, I do not find in any Myrmeleonidce a full equi- 

 valent of the cell-structure exhibited in Stilbopteryx. The form 

 of the palpi seems certainly more analogous to that of the Asca- 

 laphidce than to most of the Myrmeleonidce ; and the facies of the 

 genus reminds one much of some species of Suphalasca that in- 

 habit the same districts. 



It is, then, with much hesitation that I have omitted Stil- 

 bopteryx from the Ascalaphidce ; that I have done so is solely owing 

 to the formation of the antenna?, which finds no parallel in that 



