266 Field Museum of Natural History — ZoOlogy, Vol. X. 



flap; first dorsal ray with its tip produced, its length i.i to 1.4 in head, 

 the tips of first dorsal rays reaching slightly past those of the last rays 

 when the fin is defiexed; pectoral spines produced, their tips reaching 

 to or past middle of ventrals, their length .7 to .9 in head; ventrals i 

 to 1.2; adipose fin long, without trace of spine; caudal peduncle deep, 

 1.7 to 1.9 in head; last anal ray to caudal 1.5 to 1.7 in head; caudal 

 emarginate, the outer rays produced. 



Color brownish mottled with darker; base of anal and dorsal black; 

 a faint black bar at base of caudal rays; base of first rays of anal usually 

 with a black spot. 



This species was quite abundant in the Rio Cana at Cana. Longest 

 specimen 130 mm. This species ranges farther north than any of the 

 other species of the family. 



Family V. Pygidiidae, 



Small fishes with naked bodies, usually vilhform teeth, remote nares, 

 skull covered with sldn and muscles, no adipose fin, and a rudimentary 

 air bladder enclosed in the lateral processes of the coalescent vertebrae. 

 The family is represented by a number of genera, but only one species 

 is known to inhabit Panama. 



15. Genus Pygidium Meyen. 



Pygidium Meyen, Reise in Peru, I, 1835, 475 (type Pygidium fuscum 



Meyen). 



Body elongate, subterete; mouth terminal or subterminal; teeth in 

 bands in both jaws; maxillary with 2 pairs of barbels; a single pair of 

 nasal barbels; eyes superior; dorsal over or behind ventrals; its origin 

 overorinadvanceof origin of anal; without spine; no adipose fin; opercle 

 and preopercle with small spines; body naked; gill-membranes nearly 

 free from the isthmus or forming a free fold across it. 



Small fishes inhabiting mountain streams from Central Chili to 

 Panama and southeastern Brazil and central Argentina. 



21. Pygidium striatum Meek & Hildebrand. 



Pygidium striatum Meek & HUdebrand, Field. Mus. Nat. Hist. Pub., 



Zool. Ser.,X. 1913, 78 (Rio Cana, Cana, Panama). 



Head 4.9 to 5.75; depth 6.35 to 7.35; D. 8; A. 6. 



Body elongate; head depressed; body posteriorly compressed; snout 

 broad, its length 2.08 to 2.9 in head; eye very small, wholly superior. 



