38 



ZOOLOGY 



SECT. 



so far as known, a tailed larva, except in the genus Amviella of 

 the Molgulidee a family of the simple forms, in which the tailed 



reel 



FIG. 736. Diagram of the metamorphosis of the free tailed larva into the fixed Aacidian. A, stage 

 of free-swimming larva ; B, larva recently fixed ; C, older fixed stage, adk. adhesive papillfe ; 

 atr. atrial cavity; cil. <t<\ ciliated diverticulum, becoming ciliated funnel; end. endostyle ; 

 lit. heart ; med. ganglion of trunk ; n. gn. nerve-ganglion noto. notochor'd ; or. oral aperture ; 

 rect. rectum ; sens. ves. sense-vesicle ; stiff, stigmata ; stol. stolon ; t. tail. (From Korschelt 

 and Heider, after Seeliger.) 



stage is wanting and there is only an obscure endodermal rudiment 

 to represent the notochord. 



