230 



PROCEEDINGS OF THE ACADEMY OF 



[Apr., 



each jaw, though upper of shorter extent. Inner buccal folds both 

 wide. Lower lip wide, with slight notch at symphysis. Outer 

 barbel reaches about first sixth in pectoral spine, and inner barbel 

 extends verj^ slightly beyond tip of pectoral fin. Anterior nostril in 

 short tube about midway in snout length, and posterior simple pore 

 close behind and a little superior. Interorbital broadly convex. 

 Fontanel within interorbital, and its length about equals eye. 



Gill-opening extends forward to last third in head. Gill-rakers 

 l-f-8 short and rather blunt firm points, about f length of filaments, 

 and latter equal eye. Isthmus wide. 



Bony plates on trunk each with minute denticulations along 

 hind edges, also on spines of fins completely over their outer or 

 lateral surfaces and humeral process. Plates on head and predorsal 



Fig. 8. — Hoplosternum oronocoi Fowler. (Type.) 



region all finely striate. Coracoid plates greatly exposed, or length 

 of each about equals pectoral fin, and meeting at their anterior edges. 

 Outer half of snout, lower surface of head, and belly behind pectoral 

 plates, naked. From adipose fin 7 plates on median line of back 

 extend forward. Rudimentary caudal rays with small plates. 

 Base of each caudal lobe with 2 plates. Humeral process extends 

 back f in depressed pectoral spine. 



Dorsal origin little nearer snout tip than origin of adipose fin, 

 spine depressed and about f height of fin. Adipose fin inserted 

 about last third in space between last dorsal ray base and caudal 

 base, spine about 2 in interorbital. Caudal rounded. Anal inserted 

 about last third in space between ventral origin and caudal base, 

 depressed fin extending slightly beyond latter, and spine a little 



