80 ART. 4. r. IKE DA I 



B. — No hooks; witli 3 fixing muscles. 



a, — Eye-spots présent. No respiratory apparatus on the 



body ]->roper. lÀi\.orSi\ïox\n. ...P. japonicum. P. 5. 



1). — Eye-spots wanting-. Respiratory apparatus present 



over the surface of the body proper. Deep-sea 



form P. okinoseanu'in. P. 9. 



DENDROSTOMA. 



I, Hooks generally wanting. 



A dark-blue marking at the middle of the introvert. 3 fix- 

 ing nuiscles. Contractile villi numerous, long and branched. 



Spindle muscle posteriorly free from the body-wall 



,,D. signifer. F, 5G. 



II. Hooks present. 



A. — Tentacles short but very numerous. Hooks very large 

 (0.20 mm. higli). Contractile villi few, but remarkably long. 



3 or 4 fixing muscles D. hlamlum. P. ."53. 



B. — Tentacles relatively long, aboiit S-12 of which branch off 

 from one of the 4 main stems. Hooks small (0,04-O.OG m)n. 

 high) and about .10 in number. Contractile villi short and 



niimei-ous. Fixing muscles indefinite in number (0-3) 



I), nnnar. P. ;">?. 



PHASCOLTON. 



I. Body straight. Papillary bodies are in general small and the middle 

 part of the body proper seems almost smooth. A single 



retractor muscle with two short roots. 4 fixing muscles 



F. rcchiK. F. ir). 



II. Ijody coiled into a spiral. The middle part of the body proper cover- 

 ed with especially large papillre. 2 retractor muscles, one 

 of \vhich is nnich more slender than the other. No fixing 

 muscle /'. artificiosus. P. 18, 



