47 6 



The Tunicates, or Ascidians 



In the Botryllida and Polystydida 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. 



Fio. 282. 

 FIG. 282. Styela greeleyi Ritter. 



(After Ritter.) 

 FIG. 283. Cynthia superba Ritter. 



Cynthiidce. (After Ritter.) 



FIG. 283. 

 Family Molgvlidce. Lukanin, Pribilof Islands. 



A Tunicate from Puget Sound. Family 



These forms are often brightly colored. Botryllus gouldi is a 

 species very common along our North Atlantic coast, forming 

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

 (Zostera) and on flat-leaved seaweeds. Goodsiria dura, a repre- 

 sentative of the Poly sty elides, is one of the most common Ascid- 

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



