FISHES. 243 



Obs. The name of Thrichomydenis was first framed hy Humboldt,* under the following circum- 

 stances : Having obtained a fish from the Eio Bogota, in New Grenada, he published a memoir 

 thereon, in which he says : " Je I'ai nomme erhnophile, a cause de la solitude dans laquelle il 

 vit a de si grandes hauteurs, et dans des eaux quinesont presque habitees paraucun etre vivant. 

 Les naturalistes qui craignent que de nouvelles especcs de ce meme genre ne viennent a etre 

 decouvertes dans des situations tres-differentes, pourraient changer le nom d'eremophile en celui 

 de fh'ichomycterus, tire des barbillons attaches au nez de ce poisson." 



Thriclwmycterus , therefore, in the estimation of Humboldt, was exactly the synonym of 

 EremopMlus. 



Now, in the second volume of the same work, Valenciennes, after giving us a more complete 

 description of EremopMlus mutisii, mentions that another fish, generically distinct from the 

 above, had been obtained from Brazil, and for which he would propose the name of Thiicho- 

 mycterus, imagined by Humboldt. 



No reference to the history of this generic name being made in the Hlstoire Naturelle des 

 Poissons, we have considered ourselves fully justified in relating it here. The transfer of a 

 name to a thing for which it was not originally intended, if not explained, is liable to throw 

 a great deal of confusion upon the subject it refers to, and is likewise an infraction to sound 

 rules of nomenclature. 



Many species having been described under the name of Thrichomycterus, we would advise 

 that it should be retained, rather than to frame another one. The species of Thrichomycterus 

 are closely allied to EremopMlus, from which they chiefly differ by the presence of ventral fins. 



THRICHOMYCTERUS MACULATUS, Cuv, et Val. 

 Plate XXXIV, Figs. 1—3. 



Spec. char. Head small and very depressed, declive towards the snout, which is anteriorly 

 rounded. Mouth small. Maxillary teeth inconspicuous. Upper buccal barbel longer than the 

 lower, neither of which reaching the base of pectorals. Prenasal barbel as long as the upper 

 buccal. Opercle and subopercle prickly. Isthmus quite small. Branchiostegals, six. Caudal 

 subemarginated posteriorly. Skin perfectly smooth. Ground-color yellowish or brownish, 

 maculated with black. Fins greyish yellow. 



Stn. Thrichomycterus maculatus, Cuv. et Val. Hist. Nat. Poiss. XVIII, 1846, 493. 

 GuiCH. in Gay, Hist, de Chile, Zool. II, 1848, 311. 

 GiRARD, in Proc. Acad. Nat. Sc. Philad. VI, 1854, 199. 

 Bagre, or Vagre. Vernacular. 



Desc. The species is one of small size. The body is slender and elongated, anteriorly round'ed, 

 and slightly compressed; posteriorly more so. The greatest depth, measured immediately 

 behind the tip of pectoral fins, is contained nearly nine times in the total length, and the least 

 depth, taken on the peduncle of the tail, enters in that same length thirteen times. The great- 

 est thickness, at the anterior portion of the body, is about equal to the depth. The head is 

 contained six times and a half in the total length. It is much depressed, wedge-shaped, and 

 equally declive towards the sides. The snout is anteriorly rounded. The upper jaw overlaps 

 the lower, thus giving the mouth an inferior situation. The latter is small, and surrounded 

 with thick and fleshy lips, but little extensible upon the upper jaw. A membranous expansion 

 is to be observed at the angle of the mouth, immediately below the barbels. The latter are 

 *Eecueil d'Observations deZoologie et d'Anatomie Compar^e, &c., Vol. I, 1811, 18. 



