THE ORDERS OF TELEOSTOMOUS FISHES 479 



which had independently lost the pelvic fins (Cf . Appendix I) . 

 By successive eliminations the order has been restricted to 

 include only the Eels proper and their near allies, and the Morays. 



" The typical Apodes are unique among the so-called teleostean 

 fishes in possessing more than five basal bones in the pectoral fin — - 

 a feature characteristic of all the lower groups of Actinopterygii 

 (A. S. Woodward 1 )." They agree with the other physostomes 

 (Isospondyli, Ostariophysi, Haplomi, etc.) in the following 

 primitive characters: '(i) the air bladder (if present) communi- 

 cates with the digestive tract by a duct, (2) the fins have no 

 spines, (3) the small supraoccipital is separated from the frontals 

 by the distinct parietals. They agree with the Haplomi, Iniomi, 

 and higher Teleosts in the absence of the precoracoid (meso- 

 coracoid) arch. The Apodes are especially distinguished by the 

 following combination of characters: (1) the lack of any bony 

 connection between the skull and the shoulder girdle which is 

 in fact separated entirely from the skull. (2) The absence of 

 the premaxillaries, which are functionally replaced by the den- 

 tigerous vomer. (3) The coalescence of the vomer with the 

 ethmoid. (4) The reciprocal development of the maxillaries 

 and pterygopalatines, which functionally replace each other in 

 different families. (5) The reduction of the opercular bones, 

 which are deeply sunk in the integument. (6) The absence of 

 the symplectic, or possibly its non-separation from the hyoman- 

 dibular. (7) The absence of pelvic fins (except in the Anguilla- 

 vidas (Hay) of the Cretaceous, p. 481). (8) The multiplication of 

 the vertebrae (up to 225). (9) The anguilliform body. (10) The 

 disappearance or extreme reduction of the scales. (11) The loss 

 of the homocercal tail (vestiges of which seem to persist in Sim- 

 enchelys and which was well developed in the Cretaceous genera 

 Urenchelys and Anguillavus). (12) The union of the dorsal 

 and anal fins with the tail-fin into the gephyrocercal form. (13) 

 The occasional reduction of the vertical fins. 



The order seems to be an offshoot from some long-bodied 

 Cretaceous Actinopteran with weak premaxillaries, slender, 

 toothed maxillaries, teeth on the vomers and pterygopalatines. 

 The question of their relationship to the Isospondyli is not settled. 



iCat. Foss. Fishes, Brit. Mus., Part IV, 1901, p. x. 



