235 
In Obisium muscorum Leach there is a great difference 
-between the teeth on the 2 fingers; on the movable 
finger they are all low, half as long as they are broad 
and of the same form; on theimmovable finger 2 kinds 
of teeth are found, thuswise that most of them are 
hardly as broad, but double as high as those on the 
movable finger, and cut off at the end, while each 4th 
or 5th tooth is slightly broader at the basis, conical, 
pointed and almost double as high as its neighbour; 
finally the teeth on both fingers are largest at the 
middle, smaller towards both ends (see Zool. Dan., 
Spindeldyr, Tab. VII, fig. 6. g.). Other features are 
found in species of Roncus and Blothrus. The teeth in 
- Chthoniidæ are used a little, but by far not exhau- 
stingly, by the systematists; it is comparatively easy 
to observe them here, and they seem to vary from 
species to species. 
K. Sexual Characters. 
Croneherg has pointed out (op. cit. p. 448, Taf. X, 
fig. 1—2) essential sexual differences even visible with 
the magnifying-glass in the surroundings of the 
genital aperture in Chernes Hahnu. Similar differences 
are also found in Chelifer, Olprum, Obisium and most 
likely in all Chelonethi, but are not equally conspi- 
cuous everywhere. Balzan has pointed out. sexual 
would have seen that Chernes Hahnu C. Koch is identical 
with Ch. cimicoides Fabr., of the ,,flagellum‘ of which Stecker 
has given his poetical representation. In Arthr. Dan. he 
would have been aware of that secondary teeth are found 
on the large chele of Ch. Hahnii, that Chiridium has 11 
abdominal segments et cet — If such be the case with an 
author otherwise very carefull, it is less to be wondered 
at all the offences of the numerous less carefull authors. 
