112 FISHES OF WESTERN SOUTH AMERICA 
base and middle of ventrals; mental barbels just beyond base of pectorals, post- 
mentals to tip of pectorals; groove of fontanel scarcely perceptible; top of head and 
sides reticulate; opercle with reticulations radiating from its upper anterior corner; 
premaxillary band of teeth of nearly uniform width, the inner teeth as usual de- 
pressible; vomerine patches transversely ovate, the narrow lateral ends in contact 
with the smaller comma-shaped palatine patches; body villose, velvety, the nap 
longest in a band along the middle of the sides. 
Pectorals lanceolate; the first ray equals the length of the head less the opercle, 
reaching the ventrals; dorsal very slightly emarginate, the longest ray equal to the 
length of the first pectoral ray; base of the adipose longer than the base of the dorsal 
or anal, equal to the length of the snout and eye; caudal very deeply forked, the 
outer rays very greatly prolonged into filaments; lower ray with its filament 595 
mm. long, that is about twice the length of the fish to the base of the middle caudal 
rays; anal emarginate, the longest ray about reaching the tip of the last, equal to 
the length of the snout; ventrals less pointed than the rest of the fins, a little less 
than head without opercles. 
Top of head dark ashen, with a small light spot in the middle, immediately in 
front of the eye; eight or nine dark ashen bars, the first two nearly vertical, the rest 
extending obliquely downward and forward, the bars somewhat narrower than the 
light interspaces; the bars not quite symmetrical on the two sides, the one under 
the dorsal and the one following it joined to form a Y on the left side, the corre- 
sponding bars on the right side separate. Caudal faintly spotted, the other fins 
uniform in color. 
This species has been known hitherto from the type 190 mm. over all. The 
caudal filaments are of more uniform length, and the dorsal profile at the dorsal fin 
less arched in the type. 
55. BRACHYPLATYSTOMA GOELDIL Eigenmann and Bean 
Brachyplatystoma goeldii Kigenmann and Bean, 1907, Proc. U. 8. Nat. Mus., XX XT, 659. 
Brachyplatystoma filamentosum Eigenmann (part), 1910, Rept. Princeton Univ. Exped. Patagonia, 
III, 390. 
Peruvian Amazon 
15775, 4, 117-208 mm. to end of middle caudal rays, Iquitos, Allen, September, 1920. 
Genus 22: SORUBIM Spix 
Platystoma Agassiz, 1829, Sel. Gen. et Spec. Pisce. Bras., sp., preoccupied. 
Sorubim Spix, 1829, Sel. Gen. et Spec. Pisec. Bras., 24; 
Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 22, lima; 
Kigenmann and Eigenmann, 1890, Oce. Papers Cal. Acad. Sci., I, 212; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 392. 
Pseudoplatystoma Eigenmann (part), 1912, Mem. Carnegie Mus., V, 182. 
