Family III. Silurid.^e. g 



dd. Premaxillary band of teeth with a lateral pace 



backward extension on each side. 

 f. Lower jaw shorter than the upper; head 



not much depressed; anal rays 21 to 24 Istlarius 17 



ft. Lower jaw longer than the upper; head 



much depressed ; anal rays 1 2 to 1 5 Lcptops 1 8 



cc. Posterior nostril without a barbel; barbels 

 6, the longest not reaching eye; teeth in the 



lower jaw very weak Conorhynchus] 19 



aa. Adipose fin long, its posterior margin adnate 



to the back Rhamdia 20 



Subfamily Tachysurinae. 

 3. (ialeichthys Cuvier & Valenciennes. 



Galeichthys Cuvier & Valenciennes, Hist. Nat. Poiss., v, 28, 1840. 



(Type, Galeichthys jeliceps Cuv. & Val., etc.) 



Body more or less elongate; head armed with a bony shield above, 

 behind which is an occipital shield; skull with a fontanelle; mouth 

 rather small, the upper jaw the longer; villiform or granular, teeth 

 in each jaw; teeth on vomer and palatines; barbels 6, none at nostrils; 

 adipose fin small, its posterior margin free; caudal fin deeply forked. 



A large group of marine catfishes, especially numerous on sandy 

 shores in tropical seas. It is not known to what extent these fishes 

 enter fresh water. 



4. Galeichthys aguadulce sp. nov. Bagre. 



Type, No. 4678, F. C. M., 11% inches in length; Perez, Vera Cruz. 



Basin of the Rio Papaloapam. 



Head 3f ; depth 4^; D. 1, 6; A. 17. Body elongate, moderately 

 compressed posteriorly; head long and slender, narrow forward, its 

 greatest width i}4 in its length, not much depressed; mouth rather 

 small, its width 3 in head; upper jaw the longer; teeth in jaws in 

 villiform bands; vomerine teeth in two large patches, slightly separate 

 from each other, and without backward projection; snout 2% in 

 head; diameter of eye %y 2 in head; tip of maxillary barbel reach- 

 ing slightly past base of pectoral, outer mental barbel to gill opening; 

 gill membranes broadly connected to isthmus, their hinder margin 

 free ; top of head posterior to orbits granular ; occipital process longer 

 than broad; posterior margin of fontanelle midway between tip of 

 snout and base of dorsal spine, the fontanelle extending as a groove 

 nearly to occipital process; dorsal spine rather slender, its length 1% 

 in head; anterior margin of dorsal spine nearly smooth, its posterior 

 margin slightly serrate; anterior margin of pectoral spine smooth, 



