CHORD ATA 



449 



plexities, since the sexual generations form colonies. The 

 Salpidae are tjhe most striking example of this. The solitary 



brl 



yatt 



Fig. 262. — DoKolmn dewtiealatwm, serual generation from the left side. 

 After Herdman. 



7n?--rrfi. Mnsole bands. 

 ng. . Nerve ganglion, 



sg. Stigmata. 

 sgl. Subneural gland. 

 pbr. Peribranohial cavity. 

 atl. Atrial lobes. 



so. Sense organs. 

 brl. Brauobial lobes. 



dt. Dorsal tubercle. 

 n. Nerves. 



at. Atrial aperture. 



ov. Ovary. 



i. Intestine. 



St. Stolon of buds. 



h. Heart. 



tes. Testis. 



hrs. Branchial sac. 



end. Endostyle. 



pp. Peripharyngeal band. 



br. Branchial aperture, mouth. 



form of this family gives rise by a process of budding to a 

 chain or stolon of embryos. These become detached in larger 



Pig. 263. — Posterior part of the solitary form 

 of Salpa democratica-mucronata, showing 

 ^"'" a chain of embryos nearly ready to be set 



• free. After Herdman. 



Salpae forming the 



gem. Young aggregated 

 chain. 

 St. Stolon, 

 m. Muscle band, 

 t. Test. 

 vise. Visceral mass. 



or smaller groups, and each of them when mature produces 

 sexual organs. Their ova when fertilised give rise to the 



29 



