164 Mr. G. A. Boulenger on the Suborders and 



II. Fins without fulcra ; scales without ganoine ; vertebral centra 

 usually complete. 

 A. Supraoccipital separated from the frontals by the parietals. 



1 . Ventral fins with 10 to 16 rays. 



An intergular bone ; parasphenoid narrow .... 5. fflopidce. 

 No intergular bone ; parasphenoid very broad . . G. Albulidcc. 



2. Ventrals with not more than 7 rays. 



a. Supratemporal very large, plate-like, covering the greater 



part of the parietal bone. 



Prasmaxillary single, its posterior extremity free 

 from the maxillary ; symplectic absent ; 

 basis cranii simple 7. Mormyrida. 



Preernaxillary paired, its posterior extremity 

 firmly attached to the maxillary ; sym- 

 plectic present ; basis cranii double 8. Ilyodontidce. 



b. Supratemporal small ; maxillary firmly attached to posterior 



extremity of prsemaxillary. 

 Prsemaxillary paired ; a large hole on each side 



of the skull, between the postfrontal and the 



squamosal ; basis cranii double ; suboper- 



culum absent; ribs sessile 9. Notopteridce. 



Prsemaxillary paired; basis cranii simple; sub- 



operculum reduced ; ribs inserted on para- 



pophyses 10. Osteoglossidce. 



Prsemaxillary single ; basis cranii simple ; sub- 



operculuiu and interoperculum absent; ribs 



inserted on parapophyses 11. Pantodontida. 



c. Supratemporal small ; maxillary movable ; ribs sessile ; ven- 



tral fins below the pectorals .... 12. Ctenothrissidce t. 



B. Supraoccipital in contact with frontals. 



1. Interoperculum enormous; symplectic absent; basis cranii 



simple 13. Phractoleemidat. 



2. Interoperculum normal ; symplectic present ; basis cranii 



double. 



a. Teeth in sockets ; maxillary firmly attached to pra?- 



maxillary. 

 Symplectic exposed, fitting into a notch of the 



quadrate 14. Saurodontida; f. 



Symplectic hidden between the quadrate and 



the byomandibular 15. Chirocentridce. 



b. Teeth not in sockets. 

 Postclavicle on outer side of clavicle ; no adipose 



dorsal fin 16. Chipeida. 



Postclavicle on inner side of clavicle ; an adipose 



dorsal fin 17. Salmonida-. 



Postclavicle absent; no adipose dorsal fin 18. Alepocephalidce. 



3. Interoperculum normal ; basis cranii simple. 

 Maxillary large, toothed ; prsecaudal vertebras 

 without well-marked parapophyses ; scales 

 cvcloid or absent ; adipose dorsal fin present 

 or absent 10. Stomiatidee. 



