24 



PHYLUM TUMCATA (UROOHORDA). 



FIG. 18. Diagram illustrating the metamorphosis ot the larva of Clavelitia during and after 



fixation (f ri 1 1 Eorschell ami Eeider, after Seeliger). A Free-swi inji larva. B Larva 



just attached. C Older metamorphosed stage, ch notochord ; e atrial aperture ; ed in- 

 testine ; c/( r|ijcardium ; cs cndnsU lr ; / i-ctudcrmal fold ; ft duct of neural gland ; g ganglion ; 

 /< heart ; hp adhesive papillae ; i mouth ; A-.S gill-slits ; // atrial cavity ; r trunk-ganglion ; 

 v part j tii. 11 wall of stolon ; sb cerebral vesicle ; . cast cell 11 1< e ti>>m' of tail ; st stolo prolifer ; 

 r larv.-il tail degenerating. 



