Notes on South American catfishes, including remarks on Valenciennes And Bleeker types in the Leiden Museum

I A recent perusal of Valenciennes' accounts on the nematognathous fishes (Valenciennes in Cuvier & Valenciennes, 1839, 1840) showed that of the numerous South American species newly described or renamed, eighteen wholly or partly were based on specimens in the collection of the Rijksmuseum van Natuurlijke Historie at Leiden. It was surprising to find that most of these specimens are stated to have been sent to Leiden from Cayenne, and only a few from Surinam, for most of the pre-1839 South American catfishes in the Leiden Museum are of Surinam origin and few, if any, from Cayenne. Moreover, an examination of the collection showed that up to recently none of the specimens belonging to the pertinent species bear any indication as to a typical status. On the whole, neglecting a few omissions and additions, the same material subsequently became the subject of a large paper by Bleeker (1864), who presumed a typical status in only one case, and of a more recent review by Van der Stigchel (1946, 1947), who also distinguished only a single Valenciennes type, though nine Bleeker types (8 species) are indicated as such. Considering the importance of the actual types in this group, which in many respects is very intricate, and in view of the fact that I was able to locate sixteen of the eighteen types or type lots recorded by Valenciennes, it seems appropriate to provide here the available data and to point out a few of the serious errors that have somehow been introduced into the pertinent literature. Among the eighteen species that Valenciennes newly described or named