194 



PSYCHE. 



[April 1S89. 



in coleopteia and diptera, is not recog- 

 nizable in orthoptera." (p. 45.) 



I am not aware that any modern 

 writers have described or referred to the 

 epipharynx of the mandibulate orders of 

 insects, though I must confess that I 

 have not made extended search after 

 such references and I would be thankful 

 for information and references. Al- 

 though Dr. G. Joseph^ speaks of finding 

 them on the palate of almost every order 

 of insects, especially plant-feeding forms, 

 we are unable to find any specific refer- 

 erences, his detailed observations behig 

 apparently unpublished . 



I'he epipharnyx is so intimately asso- 

 ciated with the elongated labium of 

 certain diptera, that, with Dr. Dim- 

 mock, ^° we may, refer to the double 

 orgarn as the labrum-epipharynx : and 

 where, as in the lepidopterous Microp. 

 teryx setnipurpurella., described and 

 figured by Walter, ^^ and the pauo7pi- 

 dae^^- ( Panorpa and Borc7is) , the la- 

 brum seems pieced out with a thin, pale, 

 membranous fold which appears to be- 

 an extension of the epipharynx, l:)uild 

 ing up the dorsal end of the labrum, this 

 term is a convenient one to use. 



In the lower orders of truly mandibu- 

 late insects, from the thysanura to the 

 coleoptera, excluding those which suck 

 in liquid food, such as the diptera, lepi- 



SJoseph, Gust, Zur morphologie des gesclimackso- 

 ganes bei inseckten. Amtlicher bericht der 50 verr 

 sammlung deutscher natuiforscher u. Artzte in Mliii- 

 clien. 1S77, p. 227-22S. 



•0 Dimmock, George. The anatomy of the mouth- 

 parts and of the sucking apparatus of some diptera 

 iSSi. 



" Of. cit., tig. 3 



12 Packard, A. S. Psyche, 1889, v. Si P- 159" '64. 



doptera and hymenoptera, and the me- 

 captera {Paiiorpidaa) with their elon- 

 gated head and feeble, small mandibles ; 

 the epij^harynx forms a simple mem- 

 branous palatal lining of the clypeus 

 and labrum. It is not, so far as we have 

 observed in any mandibulate insects in 

 which the mouth parts are free, adapted 

 for mastication only, the mandibles 

 being well developed, — in such insects 

 there is no sofl: projecting or pendant 

 portion, fitted to close the throat or to 

 complete a partiall}- tubular arrange- 

 ment of the first and second maxillae. 



In all the forms, then, described 

 below, the epipharynx forms simply the 

 under surface or pharyngeal lining of 

 clypeus and labrimi, the surface being 

 uniformly moderately convex, and corre- 

 sponding in extent to that of the clypeus 

 and labrum, posteriorly merging into the 

 palatal wall of the phar}nx ; the arma- 

 tvu'e of peculiar gathering-hairs some- 

 times spreading o-ser Its base, being con- 

 tinuous with those lining the mouth and 

 beginning of the oesophagus. The su- 

 ture separating the labrum from the cly- 

 peus does not involve the epipharynx, 

 though since certain gustatory fields lie 

 under the front edge of the clypeus, as 

 well as labrum, we may in describing 

 them refer to certain fields or groups of 

 cups or pits as occup3'ing a labral or 

 clypeal region or position. 



In our descriptions we have called at- 

 tention to the shape of the front edge of 

 the labrum, whether notched or not, and 

 whether bearing traces of a median su- 

 ture, on account of the bearing of these 

 parts on the question whether the labrum 



