SOUTH AMERICAN NEMATOGNATHI. 469 



458. Corydoras elegans. 



Corydoras elegans Steiudachner, SB. Ak.Wieu, Ixxiv, 1876, Ichthyol. 



Beitrage, v, 93 (Cudajas; Teffe). 

 Habitat: Cudajas to Teffe. 



Snout compressed; head as deep as long, its width 1| 

 in its length; profile steep, little arched except at the 

 snout; fontanel long, linear, extending some distance 

 into the occipital bone; occipital process broad at the 

 base, tapering to a point, its margins straight. Top of 

 the head with numerous mucous pores. 



Eye large, \\ in the snout, 3| in the head, 2 in the 

 interorbital. Snout acute; mouth small, premaxillaries 

 expanded, covering the mouth when closed. 



Inner rictal barbel reaching about to the gill-openings; 

 lower lip broad, free, terminating in two barbels. 



Two or three azygous plates before the adipose fin. 



First plate of the lower series expanded below, with 

 the coracoid process encroaching upon the breast and 

 belly, leaving a rather narrow naked interspace. 



Distance of the dorsal spine from the snout 2 in the 

 length; the spine shorter than the head, roughened on 

 its outer margin, and near the tip on its inner margin, 

 dorsal rays higher than the spine, when depressed al- 

 most reaching the adipose fin. 



Caudal deeply forked, 2i in the length. 



Pectoral spine longer than the dorsal spine, reaching 

 to or past base of ventrals, its inner margin serrate, its 

 outer margin bristly. 



Light brown; median line of the back darker brown, 

 sometimes wanting, a broader band of dark extends from 

 the upper caudal lobe forward, broadening anteriorly; 

 two or three series of dark spots form lines near the lat- 

 eral line; these series sometimes more or less indistinct; 

 caudal and lower fins plain yellowish ; dorsal fin very 

 variable, sometimes plain light, sometimes with its base 



