HANSEN AND SÖRENSEN, THE TARTARIDES. 13 



tarsal joint. In both tribes tarsus is three-jointed and its 

 second joint the shortest. Tliese pairs terminate in two claws 

 (Pl. 2., fig. 1 f) which are similar in shape, movable and in 

 the forms hitherto known simple, without teeth. A pseudo- 

 nychium is always present; in Tartarides it is shaped as a 

 moderately small, curved, acute auxiliary claw; in some Oxopoei 

 it is a short blunt process, in other forms, for instance Hy- 

 poctonus rangunensis Oates, it is a small, curved, acute claw. 

 In Tartarides the femur IV is strongly compressed, seen from 

 the side very oblong ovate, from nearly four times to slightly 

 more than twice as long as deep; length in proportion to 

 deptli yields specific and generally sexual characters. 



In all Uropygi the first pair of walking legs is very slen- 

 der and much elongated; patella is as long as, or even — 

 in Tartarides — considerably longer than, tibia which shows 

 a secondary articulation near its base. Metatarsus and tar- 

 sus together contain in Tartarides eight, in Oxopoei nine 

 joints. The first one of these joints (Pl. 2., fig. 1 c) is very 

 short and must, in agreement with the similar structure of 

 the tibia just mentioned, be considered with the second joint 

 to be the metatarsus. 



Metatarsus is therefore two-jointed in both tribes, while 

 tarsus is six~jointed in Tartarides, seven-jointed in Oxopoei. 

 In both tribes the distal end of tarsus is rounded, without 

 an}^ real claw; as to a terminal rod or seta perhaps repre- 

 senting the rudiment of a claw we refer to our remarks be- 

 low in the paragraph on sensory hairs. In the shape and 

 position of the coxse of this pair of legs a sharp difference 

 exists between the two tribes. In Tartarides (Pl. 1., fig. 1 c) 

 this coxa is at least a little longer than, and more than half 

 as. broad as, the following pair, and its lower side is situated 

 nearly in the same plane as that of the mandibles and that 

 of the following pairs of coxa; in Oxopoei the first coxa is 

 shorter than and only half as broad as the following pairs, 

 besides it is situated in a much higher plane, viz. somewhat 

 iipwards on the side of the animal; as already mentioned, 

 these differences are connected with the difference in the 

 shape of the cephalic sternum in the two tribes. In Tarta- 

 rides the relative dimensions of several joints in this pair of 

 legs af förd specific and frequently sexual characters. — The 

 two sets of sensory hairs on the first pair of legs — and the 



