an unwarranted replacement name for Valenciennes' inermis, and tentatively placed 

 Silurus inermis Bloch in the synonymy oiAgeneiosus dentatus Kner. However, the 

 illustration in Bloch (1794) appears to have been based on a specimen oiA. 

 brevifilis. The description and illustration oiA. inermis provided by Bleeker (1862) 

 and repeated by Valenciennes (in Cuvier and Valenciennes 1840) are somewhat 

 more problematical; the specimen illustrated by Bleeker (1862: fig. 363) does not 

 especially resemble y4. brevifilis, inasmuch as the fish in his figure has a moderately 

 forked tail and an imusual pigmentation pattern that carmot be clearly assigned to 

 any known species. Because of the difficulty in ascertaining to which species the 

 name inermis was based on, and the absence of any specimens that could be 

 considered to represent types, I prefer to treat this name as a nomen dubium. 



The first revision of the Ageneiosidae included eleven species and their 

 presumed synonyms at the time (Eigenmann and Eigenmann 1890). In fact, as 

 currently recognized, only six species were apparently represented in their synopsis; 

 A. atronasus,A. brevifilis, A. brevis,A.pardalis,A. ucayalensis, andyl. valenciennesi. 

 Following the earliest period of new descriptions, summarized in the preceding 

 paragraphs, the greatest number of new species were described between 1900 and 

 1925, during which time 13 original names were proposed. These descriptions 

 mostly represented the independent work of Franz Steindachner in Austria and Carl 

 Eigenmaim in the United States, although several other authors contributed new 

 descriptions. From 1925 to 1950, an additional four putative new species were 

 described. Since 1950, there have been another four species described, all of which 

 represent junior synonyms of previously described taxa (one is currently in press). 

 This general trend is in marked contrast to many neotropical freshwater fishes, for 

 which alpha-level taxonomy has tended to favor an overall increase in the number of 

 species descriptions to the present, I attribute this to the fact that ageneiosids are 

 moderately large in size, and are mostly found in large river chaimels, where the 



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