40 Synojcfsis of the FresJi Water Fishes^ 



The distance between those two places is so great, that it ap- 

 pears hardly possible that the same species occurs at both 

 points. We have, consequently, only given in the synonymy 

 reference to the " Histoire Naturelle des Poissons," in vrliich 

 it is said to inhabit Trinidad ; as the figure of M. D'Orbigny, 

 only represents the fish found in Buenos Ayres, we have omitted 

 to refer to it. 



At a later date, Dr. E. Kner published (in the seventeenth 

 volume of the " Sitzungsberichte der Mathematisch-natiirwis- 

 senschaftlichen Classe der kaiserlichen Akademie der Wissen" 

 schaften," for June, 1855), "Ichthyologische Beitrage," con- 

 taining descrij>tions, among other Siluroids, of the species of 

 Callichthys preserved in the Museum of the Academy. In 

 that memoir he described the C. Isevigatus Yal., and drew 

 attention to the fact that the species, as described in the 

 " Histoire ISTaturelle des Poissons," and figured in the Atlas of 

 D'Orbigny's voyage, was a female, and that the C. subulatus of 

 Yal. would probably prove to be a male of the same species. 

 Dr. Kner does not positively state the place from which his 

 specimens of C. Isevigatus were procured. 



The C. subulatus of Yal. is stated by its founder to have been 

 brought from Buenos Ayres with the C. loevigatus, and also to 

 have been sent from Cayenne by M. Poiteau. There can be 

 little doubt, as Dr. Kner has suggested, that this fish is the 

 male of the C. Isevigatus. The male of the species found in 

 Trinidad corresponds as well to the description given by M. 

 Yalenciennes of his C. subulatus, as the female does to that of 

 C. Isevigatus, and if we had been positive of the identity of the 

 fish of that island, with the one of Buenos Ayres, we would 

 have placed the C. subulatus as a synonym. The proof of 

 the identity of the Buenos Ayrian and Trinidad fishes remains 

 to be satisfactorily proved, as we have already observed. The 

 specimens brought by M. Eobin from Trinidad were probably 

 dried, as in the case of Hypostomus Robinii, and had perhaps 

 lost some of their specific characters. If it should be found 



