134 



base of the 4th leg there are five sensory organs, the malleoli two- 

 on the coxa, two on the 1 rochanter, and one on the trochantella. 

 Each consists of a slender basal piece or stalk, and an expanded 

 distal piece, the blade. There is no distinct waist between the 

 cephalothorax and abdomen such as exists in the Uropygi and 

 Amblypygi. The abdomen consists of ten segments, each of which, 

 with exception of the last, bears a tergal plate above and a sternal 

 plate below ; the last or anal segment is represented by a single 

 plate marked with a vertical slit, the anal aperture. 



Generative organs open upon or behind the sternum of the 1st 

 abdominal segment, the plate showing modifications in structure 

 according to sex and age. 



Fig. 47. Lower side of trunk and of bases of appendages of Gcdcodes. a, man- 

 dibles; b, c, d, e,g, coxae of palp and of 1st, 2nd, 3rd, and 4th legs ; /, thoracic* 

 stigma; h, 1st abdominal sternum; i, k, abdominal stigmata; /, anal 

 segment ; m, trochanter, and n, base of femur of palp ; o, trochanter ; 

 p, trocbantin of 1st leg ; q, trochanter and trochantella of 3rd leg ; r, tro- 

 chanter and trochantella, s, trochantin, and t, base of femur of 4th leg ; 

 u, external malleolus. 



The respiratory organs are in the form of tubular trachea?, the- 

 stigmata of which open upon or behind the sterna of the 2nd 

 and 3rd, rarely also of the 4th, abdominal segment. There 

 is, moreover, a pair of large stigmata situated upon the ventral 

 side of the 4th segment of the cephalothorax, one on each side 

 behind the coxa of the appendage. 



Sexual characters. Male with mandibles less strongly toothed and 

 (except in one American genus) furnished above at the base of the 

 upper jaw with an organ of unknown function, thefetgellum. The 

 first abdominal sternum in the adult female consists of a single 

 plate marked with a median longitudinal groove. In the adult 



