150 Bulletin 47, United States National Museum. 



but few of the following species have been examined as to this character, 

 we are forced to refer all to the single genus Rhamdia. (Nhamdia or Bagre 

 da Rio, a Portuguese name, applied by Marcgrave to Rhamdia selce, and 

 written " Rhamdia" by Valenciennes, perhaps a misprint.) 



RHAMDIA: 

 0. Fonlanelle in the adult not continued behind the eye; maxillary band of teeth not widened 



at the edge; occipital process present. 



b. Sides with a dark lateral band; maxillary barbels reaching little beyond front of adi- 

 pose fins; pectoral spine short. WAGNERI, 233. 

 an. Species with the fontanelle undescribed, most of them probably belonging to Ithamdella. 

 c. Anal rays 11 or 12. 



d. Adipose fin moderately long, 3% to 3% in length. 



e. Maxillary barbels very long, reaching tip of ventrals. 



BARONIS-MULLERI, 234. 



ee. Maxillary barbels reaching end of dorsal. 



/. Depth 6% in length. MOTAGDENSIS, 235. 



ff. Depth 5% in length. BIIACHYPTERA, 236. 



dd. Adipose fin short, 4 in length; barbels short, not reaching tip of pectorals. 



8ALVINI, 237. 



cc. Anal rays 13 



g. Adipose fin short, about 4 in length; barbels reaching end of dorsal. 



HYPSELXJRUS, 238. 

 gg. Adipose fin moderate, 3 to 3}^ in length. 



7i. Occipital process rather short. LATJCATJDA, 239. 



Jilt. Occipital process rather long. GODMANI, 240. 



ggg. Adipose fin long, more than % of length. 



i. Barbels very long, the longest reaching middle of adipose fin. 



GUATEMALENSIS, 241. 



ii. Barbels moderate, the longest reaching front of adipose fin. 



NICARAGUENSIS, 242. 



Hi. Barbels shortish, the longest reaching end of dorsal. MICROPTERA, 243. 

 ccc. Anal rays 14 or 15. 



_/. Adipose fin long, more than % of length. MANAGUENSIS, 244. 



jj. Adipose fin medium, 3% in length. POLYCAULUS, 245. 



RHAMDELLA, (diminutive of Rhamdia): 

 aaa. Fontanelle continued backward to the occipital process, with a bridge across it behind 



the eye. 

 k. Upper jaw scarcely longer than lower; tail deep; pectoral spine about % the head. 



PETENENSIS, 246. 



Ick. Upper jaw longer than lower; pectoral spine 2 to 2 in head; dorsal spine very weak, 

 about 2^-2 in head; caudal fin about 5 in length. PARRYI, 247. 



Subgenus RHAMDIA. 

 233. RHAMDIA WAGNERI, (GUnther). 



(BARBUDO.) 



Head 4fr; depth 5 i to 7. D. I, 6; A. 9 to 11. Head flat above, with 

 vertical sides; occipital process narrow, reaching about halfway to dorsal 

 spine; maxillary barbel variable, never reaching to end of adipose fin, 

 sometimes little beyond base of dorsal; gill rakers 3 -f- 7 ; caudal deeply 

 divided; its lower lobe broad and rounded, the upper pointed. Color 

 brown, with many dark dots; a dark lateral band, darkest forward ; base 

 of dorsal pale. Rivers of Central America, on both sides of the moun- 

 tains, very abundant. (Eigenmann.) (Named for Prof. Moritz Wagner, 

 an authority in zoogeography.) 



