SECT. X. 



FLOATING ASCIDIANS. 



227 



A solitary floating Salpa is always found to contain a 

 chain of embryos joined end to end winding spirally 



Fig. 163. Salpa maxima. 



within her. They are all of one size, and portions are 

 liberated in succession through an aperture in the tunic. 

 In a little time these connected larvae are developed 

 into a chain of adult Salpse. The individuals are from 

 half an inch to several inches long, according to the 



Fig. 164. Young of Salpa zonaria, 



species, and when joined end to end the chain may ex- 

 tend many feet, but the attachment is so slight that 

 they often break up into shorter portions. The chains 

 swim with an undulating serpentine motion either end 

 foremost by the simultaneous expulsion of water from 

 the muscular tunic of each individual. A single egg is 



Q2 



