68 ENTOMOLOGISK TIDSKRIFT 1894. 



extent with a row of very fine, almost cylindrical hairs, \\hich 

 almost all were worn in the delineated specimen (PI. 2, fig. 6.) 



The mandibles (PI. 2, fig. 7 and 8) are almost triangular 

 and strongly compressed. On the upper side of the head at the 

 lateral margin close behind the labrum we see a little portion 

 (with a rather faintly developed condylus) of the mandible (PI. 2, 

 fig. 3, d) and behind it the articular membrane (f) which, more- 

 over, extends far inwards on the inferior side of the head (PI. 2, 

 fig. 4, f). Besides on this inferior side is seen a greater portion 

 of the mandible (fig. 4, d) and its inferior well developed con- 

 dylus (fig. 4, e); the rest of the mandible is overlapped by the 

 labrum and other mouth-parts. Fig. 7 exhibits the inferior con- 

 dylus (a) and the basis of the inusculus adductor (c) and unisc. 

 abductor (b). Each mandible is inwards compressed to such a 

 degree that the inner margin forms a sharp edge, the anterior 

 half of which on the mandible (fig. 7) is sinuated and incised 

 to form 5 teeth, the 3 distal of which are lying close together 

 and to a certain extent above each other, while the right man- 

 dible (fig. 8) possess but 3 teeth, all at the apex. On the inner 

 margin of each mandible somewhat in front of the posterior angle 

 is found 6—7 short setœ in a short row (fig. 7, d). 



The ma.xillcX are large and for the most part visible without 

 preparation (PI. 2, fig. 4, g, and h) with exception of the inner 

 lobe. When taken out and cleaned each maxilla is seen (PI. 

 2, fig, 11) to consist of a large cardo (s), an oblong, powerful 

 stipes with 2 lobes about equal in dimensions, and a 5-jointed 

 palpus, which is shorter than the portion of the stipes lying 

 behind its insertion. The morphological structure of the maxilla 

 is easily understood when compared with the maxilla of MacJiilis, 

 according to the interpretation of the mouth organs in Crustaceans 

 and Insects given by me in »Zool. Anzeigern. The 1st joint is 

 the cardo. The 2nd joint (2) forms the broad basal portion of 

 the stipes which tapers distally, where it is continued as the inner 

 lobe (1"), this consequently being the lateral prolongation of the 

 2nd joint. The exterior side of the maxilla is formed by an oblong, 

 triangular plate (fig. 11, a), posteriorly not quite reaching the 

 cardo and in front bearing the palpus; aslope inside and in front 

 of the distal half of this plate is found another oblong, triangular 



4 



