660 PROCEEDINGS OF THE NATIONAL MUSEUM. ' vol. xxxi. 



LUCIOPIMELODUS AGASSIZII (Sieindachner). 



The speciew resembles in g-eneral appearance Plmelodus altipinnis, 

 but ditfers in the generic characters, which are as follows: No vomer- 

 ine teeth; occipital process narrow, not reaching to dorsal plate; a 

 frontal and a small occipital fontanelle. Bones of the head striate. 

 Dorsal and pectoral spines not pungent, but obliquely segmented in 

 their distal third; the anterior margin roughened by the prolongation 

 of each segment into a small spine. Posterior margin of dorsal spine 

 smooth; that of the pectoral serrate. Adipose dorsal very long; caudal 

 widely forked; barbels Hat, slightly margined. 



Our specimen is 150 mm. long, and agrees well with Steindachner's 

 description. The head is contained 5 times in the length of body and 

 not 3 times, as given by Eigenmann and Eigenmann. 



This fish was considered a distinct genus by Eigenmann and Eigen- 

 mann, who, however, did not name it because they had no specimen for 

 direct examination. The genus was later named Perugia by Eigen- 

 mann and Xorris. The example from the Steere collection shows that 

 it is generically identical with Lnc!(>j>!)nelodus of Eigenmann and 

 Eigenmann. 



RHAMDIA QUELEN (Quoy and Gaimard) . 



Three specimens. 



PIMELODELLA CRISTATUS Muller and Troschel 



One specimen. 



PIMELODUS ALTIPINNIS Steindachner 



One specimen. 



Genus BRACHYPLATYSTOMA. 



The genus Bi'nclnjplatydoina is distinguished technically from other 

 Phnelodlndd by the character of the premaxillar}- teeth. These are of 

 two kinds, those on the anterior half of the premaxillar}^ are villiform 

 and fixed, while those on the posterior are longer, slenderer, and 

 depressible. Six species are known: Jilamentosum ^ vaillcmti, reticu- 

 lata^ roxisseaxixil^ juruense, and jjlatynema. Some of these species 

 reach a very large size. Of rotisseau.til (Goliath) Kner says that he 

 had specimens 6 feet long, and of Jilainentosuui Goeldi recorded a 

 specimen 1.95 meters long. 



B. reticulata is known to reach a length of 3 feet. 



The species change greatly with age; the young have fantastically 

 elongated maxillary barbels and caudal filaments, so that the filament 

 of the upper caudal lobe may be much longer than the rest of the fish, 

 and the maxillar}' barl)els may ])e twice the length of the fish, while 

 in the adult the maxillar\^ barbels may reach but little beyond the 

 pectorals, and the caudal filament be correspondingly shortened. 



