476 



The Tunicates, or Ascidians 



In the Botryllidw and Polystyelidcc the individuals are not 

 segmented and in the former family are arranged in star-shaped 

 groups about a common cloaca, into which the atrial siphons of 

 the different individuals open. The group springs by budding 

 from the tadpole, or larva, which has attached itself to some object. 



^ 



1^ 



i#. 



I 



Fig. 2S2. Fig. 2S3. 



Fig. 282. — Styela greeleyi Ritter. Family Molgulidcv. Lukanin, Pribilof Islands. 



(After Ritter.) 

 Fig. 283. — Cynthia superha Ritter. A Tunicate from Pugct Sound. Family 



Cynlhiidte. (After Ritter.) 



These forms are often brightly colored. Botryllns gonldi is a 

 species very common along our North Atlantic coast, forming 

 gray star-shaped masses sometimes an inch across on eel-grass 

 {Zoster a) and on flat-leaved seaweeds. Goodsiria dura, a repre- 

 sentative of the Polyslyelidir, is one of the most common Ascid- 

 ians on the California coast southward, where the brick-red 



