67 



proper with four eyes, and 'I'lijililochlhoiuiis Rnlz. willioiit eyes; llie (irsi i^roiip lins 

 according lo Balzan an ahnosi ipiadrale ceplialolhorax, and Ihe lasl has a céphalo- 

 thorax distinctly widened out in Iront, while Chthonius proper has one, which is 

 sometimes qnadrate, sometimes enlarged in front. On account of these characteri- 

 stics Balzan regards Chthonius as standing hetween the two other suhgenera; even 

 if I have not had the opportunity of examining species of all these subgenera, I 

 am inclined to believe that a good many other characters must be taken into con- 

 sideration, if we wish to get a natural classification. 



III. Specific Characters. 



Good characters for discerning the species are found everywhere; a good 

 many have already been used by the dillerent authors; the following lines just to 

 show, in which organs the best characters, the old as well as a few new ones, are 

 found. The shape of the céphalothorax, its length compared to its breadth, the 

 number and position of the eyes, but especially the dentation and aiuuiturc of 

 the front margin (cf. Daday 11. p. 190) provide good as well as easily employed 

 characters. The shape of the abdomen and the arrangement of its hairs are of 

 some value, but the genital area of the male, which varies in an exceptional 

 degree, will certainly prove of great importance. The antennae show specific 

 variations in size, in the marginal dentation of the fingers (cf. Balzan 12. pi. 12, 

 lig. 35 a) as well as in the granulation of the hand {Cht. terribilis n. sp. PI. I, fig. 1 c) 

 and so do their difl'erent appendages like the fiagellum (cf. Hansen 49. tab. V, 

 fig. 12 f, and pi. I, figs. 1 c-d) and the two serrulae (49. tab. V, figs. 12-1.^; and pi. I, 

 figs. 1 c-d). Excellent characters, but not easily investigated, are present in the 

 structure of the maxillae, especially in the sha])e of the lamina maxillaris superior 

 (cf. p. 25) as easily realised when comparing the figure (PI. I, fig. 1 t) of Cht. terribilis 

 n. sp. with the figure (fig. 2a) of Cht. Raiji L. K. The shape as well as the com- 

 parative length of the joints of the palps, but especially the armature of the fingers 

 provide valuable characters. The arrangement and structure of the hairs are per- 

 haps worth while noticing; Daday has at least in one species Cht. Wlassicii Dad. 

 (14. tab. XI, fig. 8) observed very long and slender hairs along the front margin of 

 the femoral part, which are wanting in most other species. The number as well 

 as the position of the tactile hairs of the dorsal surface of the hand show specific 

 variations, and so do those of the fingers, but less marked ones. The shape of 

 the tactile hairs is sometimes of systematic interest; in Clit. Raiji f. inst. they are 

 remarkable on account of their swollen base. 



The second and sometimes the third pair of coxae as well provide systematic 

 characters of no mean value, but inforlunately very difficnlt to investigate, by the 

 difierences, shown in the position and shape of hairs placed near to the inner 

 corner (cf. p. 66). I will mention a pair of short, curved, well articulated hairs 

 placed in the soft membrane, where the four coxae of the two last pair meet, in 

 this connection, as I have only found it in Clil. Kayi L. K. As the [jrcviously 



