HANSEN AND SÖRENSEN, THE TARTARIDES. 25 



walking legs in all Uropygi and similar groups on coxa and 

 femur of the same legs in Tartarides; a comparison of these 

 statements with the description of the lyriform organs in 

 Amblypygi (Hansen, 1. c, p. 150 — 153) will show considerable 

 difference between the two suborders of Pedipalpi in the 

 occurrence of stripes on the mandibular palps and the legs. 



Sexual Differeiices. — In Tartarides adult specimens of 

 the two sexes differ always from each other in the shape of 

 second to fourth abdominal sternite and the shape of the 

 abdominal flagellum. In the female (Pl. 1.. fig. 1 c) the posterior 

 margin of the second sternite and both margins of the two follow- 

 ing sternites are straight ; the third sternite is exceedingh^ short . 

 In the male (Pl. 1., fig. 1 p) the posterior margin of the second 

 sternite is convex, the portion at the mesial line showing a 

 very obtuse rounded angle, and a transverse suture is at least 

 sometimes observed a little in advance of the angle named, 

 so that the posterior minute middle portion of the sternite 

 is apparently a separate plate; both these margins of the 

 third and the anterior margin of the fourth are curved exactly 

 as the posterior margin of the second sternite, while the 

 posterior margin of the fourth sternite is straight as in the 

 female; the third sternite is somewhat longer than in the 

 female, but yet much shorter than the fourth. We have 

 not discovered any distinguishing feature in these sternites 

 between adult and immat ure females. 



The main points in the abdominal flagellum in males and 

 females are mentioned a bo ve (p. 15). 



The two sexes show other differences besides those descri- 

 bed, sometimes only in one part of the body, but generally 

 in. several features. Above we pointed out the sexual diffe- 

 rence generally met Avith either in the thickness or in the 

 degree of telescoping of the three posterior abdominal segments. 

 In most species, for instance in Trithyreus suhoculatus Poc, 

 all four walking legs are longer and more slender in the male 

 than in the female, and in such cases especially the difference 

 between the length of the first pair of legs in the two sexes 

 is most striking; in Schizomus crassicaudatus Cambr. the legs 

 are nearly similar in both sexes. The interiör distal angle 

 of the trochanterial part of the mandibular palps is generally 



