78 Mr. C. T. Regan on the 



2. Parapophyses co-03sified with centra. 



a. Physostomous X ; pelvic fins, if present, abdominal. 



a. Praemaxillaries nearlj' excluding the maxillaries from the 

 oral border ; body eel-shaped ; no paired fins ; verticil 



tins confluent 8. Symbranchii. 



Pectoral arch attached to the skull by a 



forked post-temporal 8 a. Symbranchoidei. 



Pectoral arch free from the skull ; no post- 

 temporal 8 6. Amphipnoidei. 



/3. Praemaxillaries absent; maxillaries articulated with the 

 fixed ethrao-vomer; quadrate fixed; pectoral arch free 

 from the skull ; body eel-shaped. 



9. Apodes. 

 Large interbranchial slits ; tongue present ; 



opercular bones well developed 9 a. Anguilloidei. 



Small interbranchial slits ; no tongue ; oper- 

 cular bones reduced 9 ft. Muraenoidei. 



y. Prcemaxillaries absent ; maxillaries meeting anteriorly and 

 suspended by the integument from a movable ethmoidal 

 rostrum ; quadrate movably articulated with the hy.i- 

 mandibular ; pectoral arch far behind the skull; body 

 eel-shaped 10. Lyomeri. 



I. Praemaxillaries excluding maxillaries from oral border; 

 parapophyses short or absent; epineurals present ; orbito- 

 sphenoid present and parietals united by suture or pofit- 

 temporals nearly meeting above supraoccipital ; an 

 adipose fin 11. Iniomi. 



t. Praemaxillaries excluding maxillaries from oral border ; 

 all prsecaudal vertebrae with strong transverse pro- 

 cesses ; no epineurals ; no orbitosphenoid ; parietals 

 separated by supraoccipital; post-temporals lateral; no 

 adipose fin 12. Microcyprini. 



b. Physoclistic ; pelvic bones not directly attached to the 



cieithra § ; orbito-sphenoid absent or vestigial ; maxillary 

 not protractile. 

 a. Lower pharyngeals completely united ; fins without 



spines 13. Syneiitoynathi. 



/3. Lower pharyngeals separate. 



* On each side a dermal plate (ectocoracoid) which in the 

 adult is united by suture to the cleithrum and co- 

 ossified with the coracoid . 14. Thoracostei. 

 ** No ectocoracoids. 



t Snout tubiform ; parietals absent ; pterotic extending 

 downwards to basioccipital. 



15. Solenichthyes. 

 Mouth toothed ; gills pectinate ; anterior 

 vertebrae elongate, with transverse pro- 

 cesses on each side united to form a shelf : 

 lower 3 pectoral pterygials enlarged . . 15 a. Aulostomoidei. 



\ Some CyprinodontidtE have recently been shown to be physoclistic. 

 § Except in the Luciocephalidae and some Anabantidae, which seem 

 clearlv related to forms with abdominal pelvic fins. 



