506 



WILLIAM K. GREGORY 



by Cope. They parallel the true Apodes x in the anguilliform 

 body, the multiplication of the vertebrae, gephyrocercal tail, 2 

 loss of the ventral fins, reduction of the scales, and especially in 

 the severance of the pectoral girdle from all connection with the 

 skull, it being far removed from the skull and attached to the 

 vertebral column. The group inhabits brackish and fresh waters 

 of southern Asia and tropical Africa, and parallels the anguilli- 

 form Dipnoi, Gymnarchs (p. 470), and Gymnotids of those 

 regions in its mud-loving habits and in the ability to respire air 

 directly. The allocation of this group to the Acanthopteroidei 

 (possibly to the Blenniidse, Boulenger) is indicated by a number 

 of characters, including the closed condition of the air-bladder, 

 the interjection between the parietals of the supraoccipital, and 

 the contact of the latter with the frontals, the presence of the 

 spines in the vertical fins, the exclusion of the maxillaries from 

 the border of the mouth. 



Appendix I. 



• Independent or homoplastic evolution of the eel-like form of body, illus- 

 trated in a list of eel-like vertebrates belonging to different families and 

 orders. 



Criteria: anguilliform body with multiplication of vertebrae, gephyro- 

 cercal tail, reduced pelvic limbs, usually predatory habits. 



SUBCLASS ORDER, SUBORDER, ETC. FAMILY OR GENUS 



Cyclise 



Marsipobrancbii Hyperotreti 

 Hyperoarti 

 Elasmobranchii Diplospondyli 



Palmospondylus 

 B dellostom idae 

 Petromyzontidas 

 Chlamydoselach us 



Incompletely anguilliform . 



Ventral fins only 

 what reduced. 



Dipneusti 

 Teleostomi 



Sirenoidei 

 Crossopterygii 

 Chondrostei 3 (?) 

 Isospondyli 



Heteromi 



Heteromi (?) 



Symbranchii 

 Apodes (proper) 



Incompletely anguilliform. 

 Tail not gephyrocercal. 



Lepidosirenids 



Calamoichthys 



Belonorhynchtts 



Stomiatidas 



Osteoglossidae (Arapaima) 



Gymnarchidse 



Notacanthidae 



Halosauridas 



Dercetidae 



Fierasferidse 



All (2 families) 



All (3 suborders and numerous families) 



1 See Appendix I. 



2 See Appendix II. 



3 The scarcity of known eel-like forms among the 

 .able. 



'anoids is remark- 



