EIGENMANN— SIXTEEN NEW PYGIDIID^. 691 



of the Indiana University, those with the letter " C." to the catalog 



of the Carnegie Museum. 



ScLERONEMA- gen. nov. 



Type, Scleronema operciilatum spec. nov. 



Allied to Pygidium. 



Ventrals nearer snout than caudal, outer pectoral rays shortest, 

 without a filament ; opercle with a long dermal flap ; interopercular 

 spines in much more restricted area than in species of Pygidium ; 

 accessory rays of the caudal inconspicuous ; maxillary barbel with 

 a large osseous base (maxillary bone). Teeth very narrow incisors ; 

 mouth wide, terminal. 



I. Scleronema operculatum spec. nov. 



7077 C, type, 79 mm. 7539 C, paratypes, 3, 65-80 mm. Cacequy, 

 Uruguay Basin. Feb. i, 1909. Haseman. 



Head 5.66; D. 12.5; A. 7.5 counting the rudimentary rays; P. 7; 

 eye in anterior half of the head ; interocular 5 in the length of the 

 head; width of the mouth nearly half the length of the head. 



Nasal barbel short, reaching just beyond posterior nares ; maxil- 

 lar)- barbel reaching about half-way to the tips of the opercular 

 spines, the bony base much longer than the soft filament ; a broad, 

 free membrane above from near the anterior nares to the tip of the 

 osseous base of the barbel, a narrower membrane along the outer 

 edge of the base of the barbel; six spines in the main row of the 

 interopercle ; opercular flap reaching to near base of the last pec- 

 toral ray; pectoral about as long as the head; origin of ventrals a 

 little nearer to the snout than to the base of the middle caudal rays ; 

 ventrals reaching beyond the anus, not quite to the anal, equal to 

 the portion of the head behind the nasal barbels ; origin of anal 

 under the antepenultimate dorsal ray, the distance from the base 

 of its last ray to the caudal four times in the length ; caudal narrow 

 and long, equal to the length of the head ; its margin slightly ob- 

 liquely rounded ; origin of dorsal over posterior half of ventrals, 



2 (XK\7)pos = hard ; vvfj-a., rb = hard thread, in allusion to the hard base 

 of the maxillary barbel. 



