VERTEBEATA 41 



Heterosomata : Pleuroiiectidse (flat-fishes). 



Plectognathi : TriacanthidEe ; Balistidfe (trigger- fishes) ; 

 Tetraodontidse (bladder-fishes) ; Diodontidge ; Ostra- 

 ciidfe. 



Pbrcomorphi: (Anacanthini) Ophidiidse ; Gad idee (cod); 

 Macruridse ; (Haplodoci) Batrachidse (toad-fishes) ; 

 (Cyclopteroidea) Cyclopteridse ; (Scatophagoidea) Sca- 

 tophagidse ; (Epilasmia) Acronuridse ; Chsetodontidse ; 

 (Rhegnopteri) Trichidiontidse ; (Distegi) Scorpsenidge ; 

 Cottidfe (sculpins) ; Blenniidse ; Gobiidse ; Platycepha- 

 lidse; Rhamphocottidse ; Agonidse; Heterognathidse ; 

 Gerreidse ; Carangidee' (pompano); Sillaginidse ; Pristi- 

 pomatidse ; Sciaenidse (maigres) ; Sparidse ; Percidse 

 (perch) ; Berycidse ; ScombridEe (mackerel); Trichiuridse ; 

 Xiphiadidse; (Labyrinthici) Osphromenidse ; Anaban- 

 tidse; (Pharyngognathi) EmbiotocidEe ; Cichlidse; 

 Labridae; Scaridse. 



Craniomi; Triglidse (gurnards); Dactylopteridse. 



The table on the following page shows that no order of 

 the Acanthopterygia has become extinct. The Percomor- 

 phi display the greatest numbers and importance at the 

 present time. The Lophobranchii and Plectognathi are 

 degenerate types. 



The geological distribution of these orders is as follows : 



Note.— The editor is indebted to Prof. Tlieodore Gill for several important 

 corrections of ambiguities in the definitions, and oversights in the arrangement of 

 the groups of fishes. None of these changes, however, affect the author's views 

 on affinities, etc. 



