1913.] 



Protostigmata in Ascidians. 



447 



f Ccesira 

 i Eugyra 

 [_ Pyura 



Boltenia 

 ^Styela 



f Dendrodoa 

 \Botryllus 



} 



Caesiridce 



Tethyum J>Tethyida5 



>Sfcyelidae 

 Botryllidae 



>Ptychobranchia. 



Chelyosoma 

 Gorella 

 Ascidiopsis 

 <J Ascidiella L 

 Phallusia 

 Phallusiopsis 

 Ciona 



Perophora 



Chelyosomatidee 



■Phallusiidae 

 Cionidse 



Perophoridse 



J^Dictyobranchia. 



(Archiascidia) | Clavehnidae 



Holozoa 

 Cystoditcs 

 Sycozoa 

 (Polycitor) 



> Polycitoridae 



Polycitor 

 Amaroucium Synoicidse 



>Krikobranchia. 



Ascidians. The stigmata of the left side are shown, the anterior end being toward the left. 



