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similar arrangement found in some auchenipterids. Quran (1989) proposed a 

 transformation series to account for the variably developed posterior epioccipital 

 process in auchenipterids; he hypothesized that a longer process, and/or one that 

 contacts the parapophyses of the complex centra is a more derived character state 

 than one in which the epioccipital process is short or does not contact the 

 parapophyses. However, Curran (1989) did not include ageneiosids in his analysis. 

 In a similar fashion, Ferraris (1988) considered various shapes of the epioccipital 

 process to represent derived states in some auchenipterids. 



At least some auchenipterids have seven vertebral centra fused to form the 

 complex centrum. This was one character that Britski (1972) and Royero (1987) 

 used to separate ageneiosids and auchenipterids, although Ferraris (1988) did not 

 mention it in his analysis. Britski (1972) qualified his use of this character by stating 

 that he did not know if fusion of seven vertebrae was uniform among all 

 auchenipterids. Nevertheless, all of the auchenipterids used as outgroups for my 

 analysis of ageneiosid relationships have seven fused vertebrae, presumably 

 representing a derived state relative to that in all of the ingroup taxa. A maximum 

 of seven fused centra has also been observed in some ariids (Howes 1983). 



Doradoids, together with ariids, mochokids, malapterurids, and some 

 pangasiids, have a unique modification of the Weberian complex generally referred 

 to as an elastic spring apparatus (ESA) by most authors (e.g.. Bridge and Haddon 

 1894, Regan 1911, Tavolga 1962, Alexander 1965, Chardon 1968, Howes 1983). In 

 most catfishes, the parapophysis of the fourth vertebra is usually a transverse 

 laminar sheet of bone that overiies the swimbladder and contacts the posttemporal- 

 supracleithral complex. In taxa with an ESA, however, the parapophysis of the 

 fourth vertebra is free from the posttemporal and has a distally enlarged plate that 

 impinges laterally or anterolateral^ on the wall of the swimbladder. The plate or 

 disc-like expansion of the fourth parapophysis is often called the Miillerian ramus. 



