PSYCHE. 



357 



condition in males and females. Mandi- 

 bles are wanting. The labrum-epi- 

 pharynx (fig. lo /. ep.) shows readily its 

 composition of two parts ; a labrum 

 which has a bifid apex projecting beyond 

 the epipharynx which bears a number of 

 taste-pits (.') and is single pointed. The 

 maxillae (fig. lo mx) are strongly chiti- 

 nized and consist of basal sclerite and 

 five-segmented palpus (the basal seg- 

 ment is short and small, but appears to 



Fig lo, MoulhpTrts of Bibio sp ; /. ep. 

 labrum epipliai 1 n\ ;h.v. innxilla. /;. labium, 

 pg panglos'-a h\p hvpopbarvnx. 



be a palpar segment rather than a palpi- 

 fer) . There is no maxillar lobe, unless 

 a short well-chitinized spur (not shown 

 in the figure) which lies interior to the 

 palpus is a rudiment of the lobe. The 

 labium (fig. lo //) is short and broad 

 presenting two well-developed, free para- 

 glossae but no glossa. The paraglossae 

 are fleshy and concave internally with 

 infolded margins, and provided with 

 numerous hairs and peculiar little 

 rugose spaces. No pseudotracheae are 

 visible. The hypopharynx (fig. lo hyp) 

 is well-developed, extending to the tip of 



the paraglossae and unusually strongly- 

 chitinized. 



Dilophits sp. A female of Dilophus 

 sp. examined shows essentially the same 

 mouthparts condition as Bibio. That 

 part of the maxilla called basal seg- 

 ment of the palpus, in the description 

 of Bibio., appears in Dilophus rather to 

 be the palpifer. 



Scatopse sp. In Scafopse sp. a re- 

 markable degree of specialization is 

 shown in the great reduction of 

 i the maxillary palpi. The palpi 



ne composed of but one seg- 

 ment, which is borne by a slender, 

 'k»' ^' well-chitinized basal maxillar scle- 

 rite The palpar segment is 

 ^TTi peculiarly pitted, and the inner 

 burface of the segment is concave ; 

 in each of the pits or depressed 

 spaces, there is a number of deli- 

 cate short papillar processes. This re- 

 duction of the palpus to a single seg- 

 ment is not elsewhere shown (to my 

 knowledge) among the Nematocera 

 although it is the characteristic con- 

 dition among the more specialized 

 Brachycera. The labrum-epipharynx, 

 labium and hypopharynx are present in 

 Siatopse and in no essentially different 

 condition from that of Bibio. The 

 paraglossae of the labium are rather 

 long and slender and with a strongly 

 chitinized supporting basal part. 



TiPULIDAE. 



In this largest of the Nematocerous 

 families we have a considerable variety 

 of mouthparts conditions, and in the 



