154 Bulletin 47 , United States National Museum. 



Occipital process narrow, reaching the bony plate at base of dorsal 

 spine. Fontanelle continued to the base of the occipital process, with a 

 bridge across it above the posterior margin of the eye. Dorsal and pec- 

 toral spines pungent ; humeral process spine-like. Dorsal rays I, 6. This 

 genus is an ally of Pimelodus and Rhamdia. The numerous species are 

 confined chiefly to the Amazon region. (Diminutive of Pimelodus; xi/ueMx, 

 fat.) 



n. Adipose fin less than % the length. D. I, G. Pectoral fins not reaching ventral, nor ven- 

 tral to anal. Pectoral spine moderate, with 8 to 15 recurved hooks. 



b. Sides with a dark lateral band which continues forward on the head. Tip of pectoral 



spine % diameter of the spine; spine very broad. CHAGRESI, 248. 



bb. Sides without dark lateral band, the color plain. Maxillary barbels reaching front 



of anal. MODESTA, 249. 



248. PIMELODELLA CHAGRESI, (Steindachner). 



Head 4f ; depth 5. D. I, 6; A. 11 or 12. Body elongate, slender. Eye 

 3 in head. Maxillary barbels reaching front of adipose fin. Dorsal 

 spine straight, scarcely roughened in front, except near the tip, 1| in 

 head. Adipose fin 3^ in length ; caudal deeply forked, upper lobe much 

 the longer. Pectoral spine flat, 1^ in head. Color brown, with a well- 

 defined band from tip of snout to middle of caudal ; dorsal fin with a 

 dark bar on the membrane upon each pair of rays. Rio Chagres. (Eigen- 

 mann.) 



Pimelodus chagresi, STEINDACHNER, Ichth. Beitr., iv, 34, 1876, Rio Chagres, at Obispo. 

 PimeUxlella chagresi, EFGENMANN, I. c., 130, 1888. 



249. PIMELODELLA MODESTA, (Gunther). 



Adipose fin long ; nearly 3 in length. Maxillary barbels reaching front 

 of anal fin ; eye 4 in head. Dorsal spine slender, little more than | the 

 head, somewhat shorter than pectoral spine; caudal forked, the upper 

 lobe the longer. (Gunther.) (Esmeraldas, Ecuador; also recorded, per- 

 haps doubtfully, from Rio Chagres.) (modestus, modest.) 



Pimelodus modestus, GUNTHER, Proc. Zool. Soc. Lond., 1860, 239, Esmeraldas, Ecuador. Gf?N- 

 THER, Cat., v, 117, 1864. 



83. PIMELODUS, Lace-pede. 

 (CONGROS BARBOSOS.) 



Pimelodus, LACEPEDE, Hist. Nat. Poiss., v, 94, 1803, (quadrimaculatus, etc.; includes various 



genera). 

 Pimelodws, CTJVIER, Begne Animal, Ed. i, 203, 1817, (quadrimaculalus, etc.; species with one band 



of teeth above). 



Pimelodus, SWAINSON, Class'n Fishes, etc., u, 305, 1839, (quadrimaculatus). 

 Pimelodus, GILL, LfJTKEN, etc., who take maculatus as type. 

 Pseudariodes, BLEEKER, Nederl. Tijdschr. Dierkunde, 1863, 99, (clarias). 

 Pseudorhamdia, BLEEKER, I. c.,101, 1863, (maculatus = clarias). 



Teeth on the vomer in small patches or none; no teeth on palatines; 

 pterygoid teeth sometimes present. Fontanelle not extending backward 

 beyond the eyes. Humeral process broad, not spine-like. Crown of 

 head granulose, or covered with thin skin. Dorsal and pectoral spines 



