SOUTH AMERICAN NEMATOGNATHI. 171 



Caudal deeply forked, longer than the head. 



Pectoral spine strongly serrated on both margins, the 

 serrations on the inner margin a little stronger; the 

 spine a little shorter than the head. Pectoral pore pres- 

 ent ; humeral process triangular, pointed behind and 

 reaching a little behind the middle of the pectoral spine, 

 its surface graiiular-striate. 



Silvery below, becoming brownish above; indistinct 

 darker markings on the back. Dark spots on the bases 

 of the dorsal rays, membrane of the dorsal transparent, 

 the tips of the rays brown, a brown spot between the 

 first and second rays in one of the specimens. A brown 

 spot at the tip of the adipose fin. Two dark spots at the 

 base and two or three brown bars on the lobes of the 

 caudal; other fins plain white. 



HeadSf; D. I, 6; A. 11. 



Two specimens .075-. 085 m. Hyavary. Bourget. 



124, Pimelodus clarias, 



Silurus clarias Block, plate 35, fig. l-2=ttarv* clarias Linnaeus in 

 part; not Silurus clarias Hasselquist which is Synodontis clarias 

 from the Nile. 



Pimelodus clarias Lacepede, Hist. Nat. Poiss. v, 93, 1803 (? 8 dorsal 

 rays); Castlenau, Amin. Nouv. Amer. Sud, 34, 1855 (Crixas; 

 Araguay, Ucayale; Amazon); Steindachner, Fish-fauna Magd. 

 Stromes, 15, 1878 (Magdalen River); Steindachner, Flussfische 

 Siidamerikas, i, 10, 1879 (Orinoco near Cuidad Bolivar), 14 

 (Mamoni River near Chepo); Steindachner, Flussfische Siid- 

 amerikas, iv, 4, 1882 (Rio Huallaga); Eigenm. & Eigenm. 

 Proc. Cal. Acad. 2d Ser. i, 134, 1888. 



Bagrus (Ariodes) clarias Miiller & Troschel, Schomburgk Brit. 

 Guiana, 627, 1848 (Waina Barima). 



Ariodes clarias Miiller & Troschel, Horse Ichthyol. iii, 10, 1849 

 (British Guiana); Kner, SB. Ak. Wien, xxvi, 1857, 413. 



Pseudariodes clarias Bleeker, Nederl. Tijdschr. Dierkunde, i, 99, 

 1863 (name only); Liitken, Meddel. Nat. Hist. Forening, 1874, 

 Nos. 1 & 2, pages 194 & 199 (Guiana). 



Silurus callarias Bloch & Schneider, "Syst. Ichthyol. in part, 379, 

 1801." 



Pimelodus maculatus Lacepede, Hist. Nat. Poiss. v, 94 and 107, 

 1801 (Rio Plata); Valenciennes, Voy. d'Orbigiiy, ix, Atlas ii, 



