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Noel M. Burkhead, et al. 
medial mental barbels rarely possess melanophores, and then only 
basally. Additionally, the maxillary barbels of 1. platycephalus usually ap- 
pear bicolored (leading edge pale, posterior edge dark), whereas in /. 
brunneus these barbels are uniformly dark. 
Fig. 3. Diagnostic features of some Virginia ictalurids: A, ventral aspect showing 
premaxillary tooth patch of Pylodictis; B, premaxillary tooth patch of I. brun- 
neus; C, premaxillary tooth patch of /. platycephalus; D, flathead bullhead dorsal 
fin with dark basal blotch; E, dorsal fin of typical bullhead; F, fin profiles of /. 
furcatus; G. fin profiles of /. punctatus; FI, fin profiles of I. catus; I, profile of an 
emarginate caudal fin. 
The premaxillary tooth patch of /. brunneus differs from /. 
platycephalus in being wider, fairly uniform in width, and usually possess- 
ing lateral edentations in the patch (Fig. 3B). The cardiform teeth of /. 
brunneus are more numerous along an anterior-posterior axis (teeth not 
forming rows) than in /. platycephalus, and occur in two distinct sizes. 
Large cardiform teeth are positioned along the anterior margin of the 
tooth patch, and are often additionally arranged in a medial, triangular 
configuration. The tooth patch of /. platycephalus usually lacks lateral 
edentations and is occasionally slightly constricted medially (Fig. 3C). 
