SOUTH AMERICAN NEMATOGNATHI. 471 



Head 3J; depth 2|-2|; D. I, 7-8; A. 7; V. 6; P. 1,8. 

 Lat. pi. I! . 



Three specimens .05 m. Rio Doce; Rio Parahyba. 

 Thayer Expedition. 



460. Corydoras aeneus. 



Hoplosoma ceneum Gill, Syn. Fish. Trinidad, 43, 1858 (Trinidad, 



W. I.). 



Callichthys ceneus Giinther, v, 230, 1864 (copied). 

 Corydoras ceneus Jordan, Proc. U. S. Nat. Mus. 1886, 560 (name 



only). 

 Habitat: Trinidad. 



This species is known only from the types. 



461. Corydoras armatus, 



Callfchthys armatus Giinther, Proc. Zool. Soc. Lond. 1868, 230, fig. 



1 (Xeberos and Huallaga). 

 Gasterodermus armatus Cope, Proc. Amer. Philos. Soc. xvii, 681, 1878 



(Nauta). 

 Corydoras armatus Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. i, 



166, 1888 (name only). 

 Habitat: Maranon and its tributaries. 



462. Corydoras paleatus, 



Callichtys punctatus (not of Bloch), Valenciennes, Voy. d'Orbigny, 

 ix, Atlas ii, pi. v, fig. 1, 1847; Cuv. & Val. xv, 318, 1840 (? Suri- 

 nam ; Monte Video). 



Callichthys paleatus Jenyns, Voy. Beagle, iv, 113, 1842 (loc. ?); 

 Giinther, v, 230, 1864 (copied); Hensel, Wiegm. Arch. 1870, i, 

 71 (Porto Alegre). 



Corydoras paleatus Eigenm. & Eigenm. 1. c. (Uraguay). 



Corydoras marmoratus Steindachner, Denk. Ak. Wien, 1879, 26, pi. 

 v, fig. 1 (La Plata). 



Habitat: La Plata and tribiitaries. 



As the description of paleatus exactly describes Stein- 

 dachner's plate of marmoratus and our specimens, we 

 have identified marmoratus with paleatus. 



Body short, chubby; ventral outline almost straight; 

 profile steep, evenly arched; occipital tapering into a 

 pen-shaped occipital process; fontanel elongate. 



Eye \\ in the snout, 3J in the head, \\ in the interor- 

 bital. Snout acute. Rictal barbels not extending be- 



