10 ENTOZOA. 



Proceros, Quatrefages ; Phagocata, Leidy ; ? Diplanaria, Darwin ; 

 PolydadMs, Blanchard ; Tiphlolepta, Oersted ; Gentrostoma, Diesing; 

 Prosticostoma, Quatrefages; Telostoma, Oersted; Gephalolepta, 

 Diesing ; Thysanozoon, Grube ; = Eolidoceros, Quatrefages ; Sty- 

 lochus, Ehrenberg ; Planocetra, Oersted. 



Rhabdocoelian group. — Turbella, Hemprich. and Ehrenberg; 

 = ? Distigma, Hemprich and Ehrenberg ; =^ ? Dalyellia, Fleming ; 

 = Amiba, Pupella, and Baphanella, Bary ; = Proteus, Miiller ; 

 Mesostoma, Duges (in part) ; = Ghonostoma, Schmarda ; Plan- 

 aria, Fabricius ; Derostoma, Oersted ; Gatenula, Dug^s ; Stron- 

 gylostoma, Oersted ; Typhlomicrostoma, Diesing ; Macrostoma, 

 Oersted ; Spirodytus, Schmidt ; Microstoma, Oersted ; DinopMlus, 

 Schmidt ; Prostoma, Oersted ; = Gyrator, Bhrenberg ; Vortex, 

 Ehrenberg ; ? Prostoma, Leidy ; ? Prostoma, Duges and Diesing ; 

 Opistoma, Schmidt; Hypostoma, Schmidt; Anotocelis, Diesing; 

 Stenostoma, Schmidt ; Schizostoma, Schmidt ; Typholana, Ehren- 

 berg ; Gonvoluta, Oersted ; Monotus, Diesing ; = Mesopharynx, 

 Schmarda ; = Monostoma, Schultz ; Proporus, Schmidt ; Biotis, 

 Schmarda ; Vorticeros, Schmidt ; Plagiostoma, Schmidt ; Spiro- 

 dytus, Schmidt ; Trigonostoma, Schmidt ; Orthostoma, Schmidt; 

 Gelidotis, Diesing ; = Sdiizoprora, Schmidt ; Nisus, Schmidt ; 

 ? Ghloraim,a, KoUiker ; ? Poseidon, Girard ; ? Scotia, Leuckart ; 

 Gatesthia, Leidy ; Megastoma, Schmarda; = Telostoma, Schmarda ; 

 Acelis, Diesing ; = Acmostoma, Schmarda ; Octocelis, Diesing ; 

 Sidonia, Schvltze ; ? Goniocarena, Schmarda; Tricelis, Quatrefages; 

 Allostoma, Yan Beneden; Gylindrostoma, Oersted; Pseudostoma, 

 Schmidt; Hypostoma, Schmidt; Tetracelis, Hemprich and Ehren- 

 berg ; Monops, Diesing ; Anarthra, Leuckart ; = Anortha, Leidy; 

 Disortts, Hemprich and Ehrenberg; Stylacium, Corda; Aphanostoma, 

 Oersted ; Bhynchoprobolus, Schmarda ; = Bhynchoscolex, Leidy. 



NemertidcB. — This family of the Turbellarians, sometimes called 

 ribbon-worms, is characterized by the presence of rounded, 

 elongated bodies, possessing an uncommon degree of sensibihty 

 and extensibihty. So remarkable is the power of extension, that 



