32 



willi the Chthoniiilae Hans.; forms with vastly difTerently shaped palps go together 

 in the different siihlaniilies like Blothriis spelaeus Sch. and Roinus alpinns L. K., 

 Gariipiis iniigatus Sim. and Garypiniis nobilis n. sp., and like Clielifer granulatiis C. K. 

 and Ch. .hwaniis Thor. In the present chaotic stale of our knowledge of the generic 

 character it is not easy lo judge definitively about the systematic value, which 

 ought to be attributed to the shape of the palps. In the one place it seems to be 

 |)retty ceitain, that a genus like Garypiis L. K. is well characterized by its long and 

 slender palps, but it seems in the other place to be very probable that Chelifer 

 Hatvaiiensis Sim. is closely related to Ch. cimicoides F. in spite of the long and 

 slender palps of the former and the rather short and clumsy ones of the latter 

 species. To the specific value of the shape of the palps every description of a 

 species of this order bears testimony; we will scarcely exaggerate in saying, that 

 the palp of one species differs in shape from that of all other species. As far as 

 the sexual difference is concerned, we find, that most forms do not provide any 

 marked differences in the shape of the palps in the sexes, while these differences 

 in a few, f. Inst. Chelifer equester With, is pushed to an extremity (cf. 21. pi. IX, 

 figs. 1 a-d). 



Tactile Hairs. The fingers of the palps always bear dorsally and posteriorly 

 tactile hairs, which are articulated in cavities, several times wider than their narrow 

 bases (cf. Hansen 49. p. 215; tab. V, fig. 14 t). These hairs are rather remarkable 

 in Chthoniiis Rayi L. K., where they are provided with a basal thickened part. 

 Similar hairs are found on the dorsal or posterior surface of the hand in at least 

 most species of the Pseiidohisiinae Hans, and Chthoniidae Hans. These hairs have 

 often been seen and figured by systematic authors like Simon, Thorell and Balzan, 

 but their systematic value was never fully realised. The number and arrangement 

 of these hairs, when they are placed on the fingers, are often characteristic f. inst. 

 in Chelifer Galatheae n. sp. (PI. IV, fig. 2 c), Ideobisium Balzanii With (21. pi. X, 

 figs. 2 d-e), /. crassinmmim Balz. (12. pi. 12, fig. 33) and Idcoroncus Mexicaniis Bks. 

 (21. pi. X, figs. 1 b-c), but these characters are not easily used, because the position 

 of the tactile hairs is not easily investigated. But the number and arrangement 

 of those, which are placed on the hand, provide an excellent and easily accessible 

 character between species and groups of species in the families in which they 

 occur, f. inst. in Ideoroncux laininatus n. sp. {P\. I, fig. 5 c), /. Mexicaniis Bks. (21. 

 pi. X, fig. 1 h) and Ideobisium Balzanii With (21. pi. X, figs. 2 d-e). 



It is easily ascertained, that the name "tactile" hairs, which has been given 

 to these organs, is a proper one. If you place two specimens of Obisinm mnscorum 

 Leach in a narrow tube, you will see them searching with their palps in all 

 directions, while they walk around; hut if the two palps under the perambulation 

 of their proprietors approach each other so closely, that the distance between 

 them is equal to the length of a tactile hair, the animals will to your surprise 

 suddenlv dart backwards awav from each other. Add lo this, thai the chilin of 



