SEGMENTATION OP THE HEAD OF DIPLOPODA. 



619 



Julus says that he believes the first body segment, i.e. the 

 post-maxillary segment, to be the apodous one. He states 

 that he believes it to be equivalent to the second maxillary 



Text-fig. 3. 



m d .- - ^ 



Ant. 



Mouth-parts of larva fifteen days after leaving the shell. 



segment in the Insecta, and also asserts that its ganglion 

 fuses early with that of the segment in front of it. I can 

 find no trace of such a fusion in either the embryos or larvte 

 of Archispirostreptus. Moreover, I have cut longitudinal 



Text-fig. 4. 



md.-^ 



mx: 



Mouth-p.'irts of larva twenty days after leaving the shell. Ant. Antenna. 

 Cly. Clypeus. Md. Mandible. Mx." Second maxilla. 



sections through the suboesophageal ganglion in several adult 

 Spirostreptus, and have found it to consist of only two 

 pairs of ganglia (PI. 37, fig. 6), namely, those of the mandibles 

 and maxillae. 



I am well aware that the evidence is incomplete and that 



