Febriiaiy--M;iicli 1SS9. 



PSYCHE. 



161 



we call the parepipharynx is apparently 

 the pale, non-chitinous, sensitive end of 

 the labrum. It is in Panorpa a palatal 

 fold or outgrowth, anel in Bore us it is 

 directly continuous with the labrum. For 

 convenience, therefore, we will call this 

 soft, non-chitinous, whitish highly sensi- 

 tive fold projecting beyond the labrum the 

 parepipharynx. And here it may be said 

 that a very close relationship appears to 

 exist between the parepipharynx oi pan- 

 orpidae and of the microlepidoptera, 

 especially the tineidae^ and in this point 

 the panorpidae are quite unlike the 

 neuroptera as restricted by Brauer and 

 myself, which do not have a par- 

 epipharynx. In fact the parepipharynx 

 appears to be mainly developed in the 

 suctorial insects, such as the hymenop- 

 tera, lej^idoptera and diptera, and also 

 the mecaptera, but is not well devel- 

 oped in exclusively biting insects, which 

 have the mandibles well developed. 



Dr. Walter's figure and account of 

 the labrum and epipharynx of JMicrop- 

 teryx seinipiirpurella is of special in- 

 terest in connection with the structure 

 of the homologous parts \nBoreus. In 

 the tineid in question, the five-sided or 

 rather triangular, narrow, horny labrum 

 is hollowed out at the end, the hollow 

 being filled by the pale, sub-membranous 

 parepipharynx, which projects out from 

 under the labrum and completes the apex 

 of the triangle made by the two organs 

 collectively. Now the labrum-epi- 

 pharynx of Bo re us and Panorpa^ is 

 rather long, narrow and triangular ; in 

 Panorpa the labrum ends in a corneous 

 point, and the epipharynx forms two 



pale, membranous flaps on each side, as 

 seen from above ; in Boreus^ however, 

 the labrum ends in an obtuse point, and 

 in fact appears at first as if hollowed out, 

 as thjrearetwo dark thickened mandible- 

 like portions on each side of the labrum, 

 free from setae and sensory pits. The 

 parepipharynx forms a pale whitish, 

 obtusely pointed projection of the end of 

 the labrum, and is not, as in Panorpa^ 

 divided into lobes extending along the 

 sides towards the base of the labrum. 



I regard the structure of the labrum- 

 epipharynx of the mecaptei^a, and on 

 the other hand the interesting discovery 

 by Walter of the primitive lepidopter- 

 ous maxilla of ^licropteryx caltella 

 with the lacinia (the homologue of one 

 half of the " tongue") and the galea, be- 

 sides the maxillary palpus, as very strong 

 proof of the origin of lepidoptera from 

 mecaptera -like forms. Walter does 

 not state how nearly the shape of the 

 galea of the Mlcropteryx in question 

 corresponds to that of the true neurop- 

 tera (in sensu Brauer) but it is notice- 

 able. 



To return to the sense-organs devel- 

 oped in the labrum-epipharynx. The 

 sensory oi'gans are of two kinds /. <?., 

 taste-cups (Will) and taste-rods, besides 

 tactile hairs and defensive setae, as well 

 as what seem to be "gathering hairs" 

 (Cheshire). 



In Panorpa debilis? the labrum as 

 seen from above is acutely triangular and 

 edged with a single, slightly irregular 

 row of long, stifi" defensive setae which 

 project a little beyond the edge of the 

 epipharynx, both in front and on the 



