240 PROCEEDINGS OF THE NATIONAL MUSEUM vol.94 



CENTROMOCHLUS AULOPYGIUS Kner 



Centromochlus mdopygius Knek, Sitzb. Akad. Wiss. Wien, vol. 26, p. 432, pi. 8, 

 figs. 25, 1858 (Efo Guapore). — Pbllegrin, Bull. Mus. Hist. Nat. Paris, 

 vol. 5, p. 158, 1899 (Apure River, Venezuela). 



CENTROMOCHLUS HECKEUI (Filippi) 



Auchenipterus heckelii Fii.ippi, Guer. Rev. ct Mag. Zool., 1853, p. 166 (ref. 



copied). 

 Centroviochlus heckelii Pellegrin, Bull. Mu.s. Hist. Nat. Paris, vol. 5, p. 158, 



1899 (Apure River, Venezuela). 



Family AGENEIOSIDAE 



Genus AGENEIOSUS Lacepfede 



Ageneiosus Lacepede, Histoire naturelle des poissons, vol. 5, p. 132, 1803. (Tj^pe, 

 Ageneiosus armatus Lacepede.) 



KEY TO THE SPECIES OF AGENEIOSUS REPORTED FROM VENEZUELA 



la. Caudal fin forked; pectoral spines pungent. 



2a. No wide black band along middle of sides continuous to base of caudal fin and 

 no trace of another black band below this one; anal base without pig- 

 ment or with just a trace; greatest depth at dorsal origin 1.6 to 1.75 in 

 the head; center of eye to tip of snout greater than distance from center 

 of eye to rear of head by the distance between anterior and posterior 

 nostrils; pectoral rays usually I, 11 or I, 12; anal rays iv, 32 to iv, 35. 



Ageneiosus caucanus Steindachner 

 26. A wide black lateral band, sometimes broken into more or less continuous 

 black blotches posteriorly, continuing to base of caudal fin; another 

 band below this anteriorly, fading into a series of small spots over anal 

 base and not reaching caudal fin; all black bands separated by wide 

 pale bands, the one above black lateral band enclosing a large black 

 blotch each side in front of dorsal fin; anal base heavily pigmented; 

 greatest depth at dorsal origin 2.0 to 2.3 times in head; center of eye to 

 tip of snout equal to distance or greater than distance from center of 

 eye to rear of head by not over 0.4 distance between nostrils; pectorals 



usually I, 13 Ageneiosus freiei, new species 



15. Caudal fin emarginate; pectoral rays not pungent; width of head about 

 1% in its length; steel-blue above, pale below; dorsal spotted; caudal with 

 pale margin Ageneiosus brevifiiis Cuvicr and Valenciennes 



AGENEIOSUS CAUCANUS Steindachner 



Ageneiosus caucanus Steindachner, Denkschr. Akad. Wiss. Wien, vol. 42, 

 p. 61, pi. 6, figs. 1, la, 1879 (Rfo Cauca). 



Ageneiosus paradalis LtJXKEN, Vid. Medd. Naturh. Foren. Kj0benhavn, pts. 

 12-16, p. 190, 1874 (Caracas, Venezuela). (Probably this is some other 

 species, but since its identity is not clear from the description by I.utken it 

 is best to leave it with caucanus where t;ther authors have referred it.) 



AGENEIOSUS FREIEI, new species 



DONCELLA 



Plate 4, B 



Ageneiosus caucanus Myers, Stanford Ichth. Bull., vol. 2, No. 4, p. 97, 1942 

 (river 10 km. south of Lagunillas, tributary to Lago Maracaibo, Venezuela). 



