168 ZOOLOGICAL PHILOSOPHY 



7. Osteoderms. [Bony skin. H. E.] 

 Ostracion (copper-fish). Diodon (porcupine-fish). 



Tetraodon (globe-fish). Spherodon. 



Ovoides. Syngnathus. 



Ordeb 2. — Bony Fishes. 

 Vertebral column with bony vertebrae, that are not flexible. 



(1) An operculum and membrane over the gills. 



Holobranchs. [Complete gills. H. E.] 



Apode Holobranchs. 



No inferior paired fins. [Eel-shaped. H. E.] 



8. Peropterous holobranchs. [Finless. H. E.] 

 Coecilia [Amphibian. H. E.]. Notopterus. 



Monopterus. Ophisurus. 



Leptocephalus [immature eel. H. E.]. Apteronotus. 



Gymnotus (Electric eel). Regalecus. 



Trichiurus. 



9. Pantopterous Holobranchs. [With all unpaired fins. H. E.] 



Muraena (eel). Anarrhichas (sea-wolf ). 



Ammodytes (sand-eel). Comephoms. 



Ophidium. Stromataeus. 



Macrognathus. Rhombus. 



Xiphias (sword-fish). 



Jugular Holobranchs. 

 Inferior paired fins situated under the throat, or in front of thoracic fins. 



10. Auchenopterous Holobranchs. [Fins on neck. H. E.] 

 Murenoid. Batrachoides. 



Calliomorus. Blenny. 



Uranoscopus. Oligopod. 



Weever. Kurtus. 



Cod. Chrysostrome. 



Thoracic Holobranchs. 

 Inferior paired fins situated under the pectorals. 



11. Petalosome Holobranchs. [Blade shaped. H. E.] 

 Lepidopus. Bostrichthys. 



Cepola (band-fish). Bostrichoid. 



Taenioid. • Gymnetrus. 



12. Plecopod Holobranchs. [Inferior fins united. H. E.] 



Gobius (goby). 

 Gobioid. 



13. Eleviheropod Holobranchs. [Inferior fins free. H. E.] 



Gobiomore. 



Gobiomoroid. 



Echeneis. 



