420 R. I. POCOCK. 



length of the femora, and the extent to which the terminal 

 segment or fang overlaps the cephalite anteriorly ; those 

 of the Lithobiomorpha in the completeness of the penulti- 

 mate and antepenultimate segments (patella and tibia), which 

 postaxially intervene between the distal extremity of the 

 femur and the proximal extremity of the fang (tarsus) 

 (PL 23, figs. 1—3). 



The pleural sclerites of the toxicognaths extend as far 

 forwards as the anterior border of the tergum of the 

 toxicognathic somite, but fall far short of the proximal 

 end of the femora (PI. 23, figs. 1, 3, }jI.). 



The tergum of the toxicognaths (= basal plate) resembles 

 that of some Greophilomorpha (e.g. Mecistocephalus) in 

 size; it is as wide as the cephalite, which it underlies in front, 

 but mnch narrower than the tergum of the first pediferous 

 somite, which it overlaps behind (PI. 23, figs. 1, 3, bp.). 



The pediferous somites differ from those of all 

 Chilopoda hitherto known, in that the tergal plates are 

 numerically in excess of the sternal, the latter being 

 fifteen in number, as in the Lithobiomorpha, and the former 

 twenty-one, as in most Scolopendromorpha. 



The terga are unequal in size, but not alternately larger 

 and smaller ; the first is very large, and considerably over- 

 laps the second, the fourth overlaps the third in front and 

 the fifth behind, the seventh overlaps the sixth in front and 

 the eighth behind, the ninth meets the tenth without distinct 

 overlap, the twelfth overlaps the eleventh in front and the 

 thirteenth behind, the fifteenth overlaps the fourteenth in 

 front and the sixteenth behind, the remainder normally over- 

 lapping the anterior border of those that succeed them, 

 the overlapped area being smooth and defined by a transverse 

 groove ; the tergum of the last somite is completely coalesced 

 with the chitinised pleural area. 



The pleural surfaces of all the pediferous somites, except 

 the thirteenth, fourteenth, and fifteenth, are furnished with a 

 distinct prtecoxal sclerite (^epimeron of Latzel) ; the stigma- 

 tiferous somites are furnished in addition with a usually" smaller, 



