I $6 DR. K. W. VERHOEFF ON BRACHYCHAETEUMA, 



gradually thickened towards the end and slightly grooved 

 longitudinally at the end itself. 



If we compare this stage of Titanosoma with the same stage, 

 already well-known, of Polydesnms, and especially with the 

 one given by Latzel on page 52 of his work on Diplopods, we 

 find an agreement in many details. In two points however 

 there is an important difference; firstly in that the second 

 Polydesmus-larvse possess only " nine " abdominal segments, 

 but especially in the dissimilar increase in the number of 

 pairs of legs. In the possession of three, six, eleven and 

 seventeen pairs of legs in the first to the fourth larval stages 

 there is agreement between the two genera; but in Polydesnms 

 the fifth to the seventh larvae increase their pairs of legs in the 

 female from twenty-three to twenty-seven and twenty-nine, 

 whilst it is remarkable that the fifth and sixth Titanosoma 

 larvas lag behind, with twenty-one and twenty-three pairs of 

 legs respectively. Still more remarkable, and conclusive as 

 evidence of sexual maturity, is the fact that Titanosoma in the 

 seventh stage suddenly acquires twenty-nine pairs of legs. It 

 will be seen further from what has already been said that a 

 condition with four (five) legless posterior segments continues 

 uniformly in Titanosoma from the second to the sixth larval 

 stage. On the basis of the statements made above, the 

 Titanosoma larvae may easily be separated into the following 

 divisions : — 



(a) Large bristles on ~\ 



the pleurotergites ; >• 1st larva 



5-jointed antennas ) 



(b) Small bristles on 

 the pleurotergites ; < 

 7-8 jointed antennae 



4 (5) legless pos- 

 terior segments 



7-jointed 



antennae 2nd~4th larva 



8-jointed 



antennae 5th-6th larva 

 2 (3) legless pos- 

 terior segments Adult with 19 



abdominal 

 segments 



The jointing of the antennae of Titanosoma deserves special 

 consideration, because it offers us a favourable opportunity of 



