24 TELEOSTEI. 



IV. HAPLOMI. — Air-bladder, if present, communicating with the digestive tract by a duct. 

 Opercle well developed. Pectoral arch suspended from the skull ; no mesocoracoid arch. 

 Fins usually without spines ; ventrals abdominal, if present. Anterior vertebrae distinct, 

 without Weberian ossicles. 

 Mouth protractile ; head scaly . . 10. Cypbinodontid^e. 



V PERCE SOCES. — Intermediate between the preceding and the following suborders. Air- 

 bladder without open duct. Ventral fins abdominal, or, if under the pectorals, with the 

 pelvic bones not solidly attached to the clavicular bones. 



A. Two well-developed dorsal fins, the anterior small and formed of spinous rays ; pectoral 



fins inserted high up. 

 Pelvic bones free or connected with the clavicles by ligament ... . 11. Athebinid,e. 

 Pelvic bones suspended from the postclavicles 12. Mugilid^e. 



B. A single dorsal fin. 



No spines to the fins 13. Ophiocephalid^e. 



Strong spines to the dorsal, anal, and ventral fins 14. Anabantid^e. 



VI. ACANTHOPTERYGIL— Air-bladder usually without open duct. Opercle well developed. 

 Fins usually with spines, the ventrals thoracic or jugular^ more or less firmly attached to 

 the clavicular arch. Pectoral arch suspended from the skull ; no mesocoracoid arch. 

 Anterior vertebras distinct. 



A. Scapula and coracoid well developed. 



Two nostrils on each side ; lower pharyngeal bones usually distinct . . 15. Seebanld^e. 

 A single nostril on each side ; lower pharyngeal bones united .... 16. Cichlid^e. 



B. Scapula and coracoid more or less reduced. 



Spinous dorsal, if present, formed of a few flexible rays 17. Gobiid^e. 



VII. OPISTHOMI. — Air-bladder without open duct. Opercle well developed, hidden under the 

 skin. Pectoral arch suspended from the vertebral column, far behind the skull; no 

 mesocoracoid arch. Vertical fin with spines, no ventrals. Anterior vertebras distinct. 



A single nostril on each side 18. Mastacembelid^e. 



VIII. PLECTOGNATHI. — Air-bladder without open duct. Opercular bones more or less 

 reduced; maxillary and prge in axillary bones often firmly united. Pectoral arch suspended 

 from the skull ; no mesocoracoid arch. No ribs. Ventral fins thoracic and much reduced, 

 if present. Anterior vertebrae distinct. 



Teeth forming a beak with a median suture ; no ventral fins ; body 



inflatable 19. TETEODONTLDiE. 



For the convenience of the student who wishes to quickly determine the family to 

 which any given fish may belong, without troubling about anatomical characters, a 

 second synopsis has been prepared. 



