Jordan and Evermann. Fishes of North America. 129 



continued as a deep groove to base of occipital process ; maxillary barbels 

 reaching axil; snout blunt; vomeriue teeth in 2 small, separate patches, 

 contiguous to the larger palatine patches ; gill rakers 6 -f- 9. Caudal 

 deeply forked. Inner surface of paired fins black. Panama; two speci- 

 mens known. (Named for David Starr Jordan.) 



Tuchisunu jordani, EIGENMAXN & EIGENMANN, Proc. Cal. Ac. Sci., 1888, 142, Panama ; EIGEN- 

 MANN, S. A. Nematognathi, 79, 1890. 



189. HEXANEMATICHTHYS C^ERULESCENS, (GUnther). 



Head 3 to 3. A. 17. Palatine patches of teeth small, scarcely larger 

 than the vomerine patches which are oval and widely separated on median 

 line; occipital process broader than long; head as wide as long; eye 

 6 in head, 2 in snout, 3 in interorbital width ; maxillary barbels to mid- 

 dle of pectorals; occipital process keeled, subtruncate posteriorly; dorsal 

 spine 2 in head ; pectoral spine equal to head without snout ; upper caudal 

 lobe about as long as head. Steel blue ; fins largely black. West coast 

 of Guatemala. (Giinther.) (Latin, bluish.) 



Arius csendescens, GUNTHER, Cat., v, 149, 1864, Rio Huamuchal, Guatemala. 



190. HEXANEMATICHTHYS GUATEMALENSIS, (GUnther). 



Head 3f . A. 18. Palatine patcheo of teeth much larger than vomerine; 

 fontanelle almost obsolete, ending between the eyes, and not prolonged 

 into a groove ; head f as wide as long ; body slender ; fins mostly dusky; 

 caudal about as long as head ; body slender. Mazatlau to Central America; 

 not rare. 



Arins yiiatemalensis, GUNTHER, Cat., v, 145, 1864, Guatemala; Chiapas. 

 Arius guatemalensis, JORDAN & GILBERT, I. c., 48,1882. 



191. HEXANEMATICHTHYS ASSIMILIS, (Gunther). 



Fontanelle short and narrow, ending midway between tip of snout 

 and middle of dorsal plate ; head as wide as long. D. I, 7 ; otherwise 

 essentially as in H. guatemalensis. (Gunther). Atlantic coast of Central 

 America, ascending streams, (assimilis, similar.) 



Arius assimilis, GUNTHER, Cat., v, 146, 1864, Lake Yzabal, Guatemala. 

 Arius assimilis, JORDAN, Proc. Ac. Nat. Sci. Phila., 1883, 281. 



192. HEXANEMATICHTHYS SURINAMENSIS, (Bleeker). 



Head 3? ; depth 6. D. 1,7: A. 18. Palatine bands of teeth without 

 backward projecting angle; teeth all villiform, those on the palate in 4 

 patches, the vomer and palatine patches sometimes contiguous. Granula- 

 tions of the head continued forward to between the eyes. Fontauelle not 

 continued backward as a groove; interorbital area without ridges ; adipose 

 fin about as high as long, shorter than the dorsal fin. Depth of head 1 in 

 its length ; width 1. Eye 5 in the head, 2^ in the interocular, less than 

 2 in snout. Occipital process not longer than broad, not conspicuously 

 keeled. Snout depressed ; upper jaw little longer than lower. Vomer and 

 palatine teeth contiguous. Maxillary barbels reaching to the base of the 



F. x. A. 10 



