10 BNTOZOA. 



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

 PolycladuSj^laTOLchardi; Tiplilolejota, Oersted; Centrostoma,Diesmg; 

 Prosticostoma, Quatrefages ; Telostoma, Oersted ; Cejphalolepta, 

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

 locJius, Ehrenberg ; Planocetra, Oersted. 



Rhabdocoelian group. — Turbella, Hempricli and Ehrenberg; 

 = ? Distigma, Hempricii and Elirenberg ; = ? Dalyellia, Fleming ; 

 = Amiha, Puijella, and Baphanella, Bary ; = Proteus, Miiller ; 

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

 aria, Fabricius ; Derostoma, Oersted ; Gatenula, Duges ; Stron- 

 gylostoma, Oersted ; Tyjjhiomicrostoma, Diesing ; Macrostoma, 

 Oersted ; Sinrodytus, Schmidt ; Microstoma, Oersted ; Dinophilus, 

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

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

 Opistoma, Schmidt; Sypostoma, Schmidt; Anotocelis, Diesing; 

 Stenostoma, Schmidt ; Schizostoma, Schmidt ; TypJiolana, Ehren- 

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

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

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

 clytus, Schmidt; Trigonostoma, Schmidt; Orthostoma, Schmidt; 

 Gelidotis, Diesing ; = Schizoprora, Schmidt ; Nisus, Schmidt ; 

 ? Ghloraima, KolHker ; ? Poseidon, Girard ; ? Scotia, Leuckart ; 

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

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

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

 Allostoma, Yan Beneden; Gylindrostoma, Oersted; Pseudostoma, 

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

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

 Disorus, Hemprich and Ehrenberg; Stylacium, Oorda; Aphanostoma, 

 Oersted; liliyncliopjroholus, Schmarda; = Rliynchoscolex, Leidy. 



Nemertidm. — This family of the Turbellarians, sometimes called 

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

 elongated bodies, possessing an uncommon degree of sensibility 

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



