HANSEN: ON SIX SPECIES OF KOENENIA. 215 



obtuse apex. But tliese differences in the number and especially 

 in the shape of the teeth — • or spines, as they are named in 

 the descriptions of the species — are always rather slight and 

 difficult to observe with certainty (the chela must be cut oft" and 

 its fingers removed somewhat from each other by preparation) 

 and therefore of slight value as distinctive character between 

 the species. But other species hitherto unknown may perhaps 

 possess another number of teeth. 



Among the appendages the palpi and the first and the last 

 pairs of legs öfter very practical and solid characters, not only 

 in the difterence between length in proportion to thickness in 

 some of the joints (f. inst. the tibia in the palpi and in the first 

 pair of legs, the last tarsal joint in the first pair of legs), but 

 besides in the relative length of two joints in the same appen- 

 dage, and in this respect the joints in the metatarsus and tarsus 

 of the palpi and of the last pair of legs are very valuable and 

 must be drawn with care in all species. And in more than half- 

 grown immature specimens I have found the same differences 

 between the length of the joints as in tlie adult animals. That 

 the thickness of the appendages is rather difterent in various 

 species is easily seen on the plates, but this is most easily appre- 

 hended and described by pointing out the proportion between 

 length and thickness (both dimensions measured) in some of the 

 joints. — In the number of joints in the appendages all species 

 agree with A', mirabilis. 



The large sternum between the first pair of legs is in all 

 species adorned with a lesser number of short, plumose hairs. 

 The number of these hairs varies much from species to species, 

 but very little or — when the number is low — not at all be- 

 tween specimens of the same species, and the arrangement of 

 the hairs is also very difterent. A comparison between several 

 figures (fig. I a and 2 a on pi. 2, fig. 2 b and 3 c on pi. 3, 

 fig. 2 a on pi. 4) elucidates these differences which offer practi- 

 ■cal characters. 



The hairs and setce on the ventral side of the abdomen 

 present excellent characters in the adult animals. The hairs 

 on the second segment and its lobe have been already mentioned. 

 The fourth, fifth and sixth segments — and to a lesser degree 



