the laminar process of the quadrate, the only synchondral articulation being a short 

 cartilaginous bar at its posteroventral comer. The suprapreopercle is a small, rod- 

 like element, investing a short portion of the preopercular latero-sensory canal 

 anteroventral to its exit from the pterotic. The preopercle is a moderately large 

 blade, smooth on all margins, and sutured anteroventrally with the quadrate. The 

 preopercular latero-sensory canal gives off a posterior branch and a ventral branch 

 before exiting at the anteroventral comer, below and behind the condyle 

 articulation with the anguloarticular of the lower jaw. 



There is one additional element of the suspensorium in ageneiosids that 

 deserves some comment. The bone in question is situated anterior to the 

 metapterygoid and posteromedially to the palatine. In the literature on siluriforms 

 there is considerable confusion associated with the terminology and homologies of 

 the anterior suspensorial bones, or the pterygoid complex, as discussed in greater 

 detail by Goshne (1975), Howes (1983) and Schaeffer (1987). An exhaustive review 

 of the problem is beyond the scope and intent of this work. Fink and Fink (1981) 

 stated that in catfishes the ectopterygoid is greatly reduced and that the 

 mesopterygoid is also reduced and not in contact with the rest of the suspensorium 

 posteriorly. In several groups of siluriforms the ectopterygoid has been lost 

 altogether, and the endopterygoid is variably reduced or absent (Lundberg 1982, 

 Schaeffer 1987). Regan (1911) diagnosed the neotropical doradoids as lacking a 

 pterygoid, but having a mesopterygoid that connects the metapterygoid with the 

 lateral ethmoid. Following Regan, Chardon (1968) included the absence of a 

 pterygoid in his definition of the various families, but he termed the bone an 

 entopterygoid. Ferraris (1988) called the lost element an ectopterygoid, and 

 homologized it with the element of the same name in other teleosts (after Fink and 

 Fink 1981). Loss of the ectopterygoid, then, is a character shared by all doradoids, 

 but it has been independently lost in a number of other families. The question 



