STRUCTURE OF ONYCHOPHORAN HEAD BUTT 



57 



strata the presence of two widely spaced but much smaller ventral 

 organs lying anterior to and underneath the antennal lobes. How- 

 ever, these anterior ventral organs apparently never reach a size suffi- 



FiG. 5.— Development of onychophoran head. 



A, B, C, stages in development of Peripatus capensis, adapted from Sedgwick. 

 D, older embryo of Peripatus cdzvardsi, adapted from Kennel. 



Ant, antenna; Dl, dorsal lobe; Fcl, feeding claw; Orp, oral papilla (Sedg- 

 wick) ; Ps, preoral somite (Sedgwick) ; Vo, ventral organ. 



cient for them to be seen in whole mounts of the embryo, since they 

 have not been reported by previous workers. Thus the brain appears 

 to be composed of three ganglionic centers, the optic lobe, the antennal 

 lobe, and a third pair of lobes with nerves given oflf to the stomodaeum 

 and the feeding claws. According to Pflugfelder, Plate in 1922 recog- 



