Figure 48. The development of the ascidian Phallusia 

 mammitlata (by Krohn) . 



A — late embryo with two pigmentation spots: a — body; 



b — beginning of the tail; c — rudiment of upper sucking 

 processes? d, e — anterior and posterior pigmentation 

 spots . 



B — larva, side view: a— tunica with green bodies; bb— the 

 axis of the tail; cc — its canal; d — horizontal half; 

 e, f — anterior and posterior pigmentation spots; 

 g — right anterior; h — posterior sucking processes. 



C — Phallusia in the process of metamorphosis: a— widely 

 opened respiratory siphon; bb— posterior (constrictor) 

 siphons; c — nervous ganglion with the nervous branches; 

 d: — digestive tract; e — stomach; f — intestine; g — situating 

 coil of the larval tail; hhhh — first two pairs of gill 

 openings of the respiratory sac; i — pigmentation mass over 

 the nervous ganglion; k — ventral fissure; 1, 1 — tunica. 



596 



