282 CALIFORNIA ACADEMY OF SCIENCES. 



Mental barbels less than one-third the length of the 

 head: 



Dorsal spine 1| in head, its anterior margin smooth, 

 except near the tip, its posterior margin slightly serrate. 



Caudal broken. 



Anal rays crowded, gradually decreasing in height 

 backward, the margin undulating. 



Pectoral spine very strong, 3J in the length. 



Dark brown; ventral surface dusky, with numerous 

 dark points; dorsal fin with dark spots, most prominent 

 near the free margin; tips of ventrals dusky, the base 

 profusely dotted, the intermediate region almost plain 

 yellowish; pectoral fin profusely spotted. 



Head 4; depth 4f; D. I, 6; A. 41; V. 6; P. I, 7. 



XLIX. AUCHENIPTERICHTHYS. 



Auchenipterichthys Bleeker, Nederl. Tijdschr. Dier- 

 kunde, i, 89, 1863 (thoracatus). 



Type: Auchenipterus thoracatus Kner. 



Caudal obliquely truncate or rounded, jaws subequal. 

 Barbels six, those of the mandible disposed in two pairs. 

 Teeth villiform, none on vomer or palate. Eye large, 

 lateral, covered with skin. Adipose fin very short; dorsal 

 fin with a spine and six rays. Anterior rays of anal in the 

 6 elongate, bearing the urogenital organ. Ventral fins 

 free, with 9 rays. Pectoral spine strong, serrated on both 

 margins. Occipital process firmly joined to the dorsal 

 plate. Anterior orbital bones prominent. Head wider 

 than deep, the bones granular, the sutures distinct. Pec- 

 toral pore present. 



Habitat: Amazon. 



225- Auchenipterichthys thoracatus, 



Auchenipterus thoracatus Kner, SB. Ak. Wien, xxvi, 425, pi. vii, fig. 22, 

 1857 (Rio Guapore). 



