2 14 ENTOMOLOGISK TIDSKRIFT I9OI. 



In a rather large but immature specimen of K. sianicnsis 

 the genital lobes are fully developed, there is an impression, 

 but no real slit — no genital aperture — between them, and 

 their hairs are less numerous than in the adult female : further- 

 more the hairs on the ventral surface of the fourth, fifth and sixth 

 segments are reduced in number with one pair or with two pairs, 

 and the eleventh segment has only eigth setae, while ten are 

 present in the adult. Similar reduction is certainly found in 

 immature specimens of all species. 



g. Characters and their value. Of all the differences 

 between the species examined by me the presence or absence of 

 abdominal ventral sacs is, in my opinion, the most curious. But 

 being unable to combine this feature with other characters I 

 thought it most correct not to establish a genus for the reception 

 of the American species which possess these sacs. On the pre- 

 ceding pages attention has been drawn to a series of characters: 

 number and shape of the lateral sense-organs on the head, diffe 

 rences in the structure and number of joints in the tlagellum, 

 differences in the number and arrangement of the hairs on the 

 ventral side of tlie second abdominal segment with its genital 

 lobe, differences in the place of insertion of the stiff seta on 

 the third metatarsal joint of the first pair of legs, differences 

 in the length of the sensory seta on the metatarsus of the last 

 pair of legs. 



But it may perhaps be convenient to mention the other 

 characters I have found. 



The number of processes or teeth on the two fingers of the 

 antennal chela offers apparently a character: in some species I 

 have found nine, in others only eight well-developed teeth on 

 each finger — always the same number on both fingers — ])e- 

 sides one or two which are ([uite rudimentary. Furthermore the 

 shape of the teeth öfters some difterence: in /v. Wlicclcn the 

 teeth (pi. 2, fig. 2 c)^ the distal ones excepted, are rather broad 

 and present on the proximal side a feeble incision at a short 

 distance from the acute apex, so that a secondary very small 

 apex is formed on the posterior margin. In A. aiigiista (pi. 4, 

 fig. I c) this feature is more feebly developed, and in K. Grassii 

 (pi. 4, fig. 3 d) it is not found, all the teeth being slender with 



22 



