652 ON THE CLASSIFICATION OF THE TUNICATA. 



The species which are sufl&ciently known can be distinguished 

 thus : — 



("The tail bifurcated at its extremity 1 



\ Tail not forked ^ 



(With long posterior processes, forks of tail not narrow. 

 F. furcata, Vogt. (Med.) 

 With short posterior processes, forks of tail narrow. 

 F. megachile, Fol. (Med.) 



o fBody bent at an angle, mouth 6-lobed. F. formica, Fol. (Med.) 

 \ Body sti-aiglit, mouth not lobed 3 



(Body 2'25 mm. long, stinging-cells in integument. 

 F. tirticans, Fol. (Med.) 

 Body ri5 mm. long, no stinging-cells... F. haplostoma*, Fol. (Med.) 



KoWALEVSKIAf, Fol, 1872. 



Body ovoid, truncated anteriorly. 

 Tail large, lanceolate and pointed. 

 Endosfyle and heart absent. 

 PJiarynx with four rows of ciliated processes. 

 Intestine absent, except the rectum. 



This remarkable genus contains a single species, Kowalevshia 

 tenuis, Fol, from the Mediterranean. 



AppendiculariidsB have been found in nearly all seas of the 

 world; but most of the forms recorded or preserved cannot 

 now be referred to their proper species. 



* Appendicularia acrocerca of Gegenbaur. 



t This genus has such exceptional characters, that it might be separated from 

 the Appendiculariidte as a distinct family. 



