* Gordon Howes Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Introduction 1 Notes on counts and measurements 2 Catalogue of nominal species 2 Species groups 46 Acknowledgements 47 References . 47 Introduction As presently recognized Brycon is one of the largest neotropical characoid genera, containing over 60 nominal species of which perhaps 40 or so are 'valid' species. The genus is ill-defined, being recognized by a combination of what are most likely plesiomorph characters, ie. the presence of two inner symphysial teeth in the lower jaw, 3 or 4 rows of premaxillary teeth, premaxillaries linked via a convoluted symphysial joint. These characters occur in other Neotropical and African characoids and, moreover, may be lacking in some species assigned to Brycon. There is a wide diversity of cranial and dental morphology within the genus and it is questionable whether Brycon as it now stands is a monophyletic unit. This is a question to which the author has addressed himself and although some progress toward an answer has been made, it is clear that before any polarity can be applied to the salient characters identified, many more in-and out-group comparisons have yet to be made. Thus, study of phylogenetic relationships of Brycon will not be completed for some years. During the course of this phylogenetic study most of the literature concerning the genus has been consulted and indexed together with data on many type specimens examined. Since no revision of Brycon has ever been published nor (since Eigenmann, 1910) has a complete list of species been compiled, I felt it opportune to present these collected data in the form of a review in the hope that it will serve as the basis for a future revision. For the purpose of this review, a broad generic concept of Brycon is retained, viz: fishes possessing a rhinosphenoid; a single medial symphysial tooth in each dentary; 3 or 4 rows of premaxillary teeth (sometimes modified so as to appear as two rows) with the two teeth forming the inner row enlarged; principal jaw teeth tri-quinquicuspid but sometimes with the lateral cusps reduced so as to appear virtually unicuspid; the premaxillaries joined at the symphysis by a convoluted interlocking joint (with a single exception); maxillary valve tissue often papillate and convoluted; posterior myodome open ventrally with part of the eye musculature taking its origin from the basioccipital rim; frontal and parietal fonantelle present at least in juveniles; coracoid not enlarged; supramaxilla absent (the absence of Bull. Br. Mus. not. Hist. (Zool.) 43 ( 1 ): 1-47 Issued 29 July 1 982
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