12 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



Ictahirus meridionalis Jordan & Evermann, Bull. 47, U. S. Nat. 

 Mus., 1896, 135. 



Large streams on the Atlantic side of the Isthmus of Tehuan- 

 tepec. (Otopa.) 



Head 4 to ^%\ depth 5 ; D. i, 6; A. 28 to 29. Body elongate; 

 head }4 to y$ longer than broad; snout obtusely rounded, the upper 

 jaw longer than the lower; premaxillary teeth in a band, 5 or 6 

 times as broad as long; maxillary barbels reaching to end of 

 head; outer mandibular barbels reaching to posterior margin 

 of gill membranes; distance of origin of dorsal fin from tip of 

 snout 2 to 2% in its distance from caudal fin, its spine finely 

 retrorse-serrate on posterior margin; length of base of adipose 

 fin equaling that of dorsal, the fin short; pectoral spine strongly 

 retrorse-serrate on inner margin, its length i^ i n head, the spine 

 stronger and a little shorter than the dorsal spine ; pectoral fin longer 

 than ventral, i^ in length of head; ventral extending to origin 

 of anal fin; caudal fin deeply forked. 



Color brownish above, with steel blue reflections; lower half of 

 body silvery, with a reddish tinge and finely punctulate with dark 

 dots. Length of adults not known. 



One specimen 5^ inches in length was taken in the Rio Otopa 

 at Otopa. 



5. Amiurus Rafinesque. 

 THE HORNED POUTS. 



Ameiurus Rafinesque, Ichth. Ohiensis, 65, 1820. (Type,Pimelodus 

 cnpreits Rafinesque = Pimelodus natalis LeSueur.) 



Haustor Jordan & Evermann, Bull. 47, U. S. Nat. Mus., 1896, 

 135. (Type, Qadus lacustris Walbaum.) 



Body moderately elongate, robust anteriorly, the caudal peduncle 

 much compressed; head large, wide; supraoccipital extended back- 

 ward, terminating in a more or less acute point, which is entirely 

 separate from the second inter-spinal buckler; skin covering the 

 bones usually thick; mouth large, the upper jaw in most species the 

 longer; teeth in broad bands on the premaxillaries and dentaries; 

 band on upper jaw convex in front, of equal breadth and without 

 backward prolongation; adipose fin short, its hinder margin free; 

 anal fin of 15 to 35 rays; caudal fin usually short, truncate or 

 deeply forked; lateral line usually incomplete; all Mexican species 

 so far known, except one (Amiurns natalis}, with a deeply 

 forked caudal fin. 



