ANNOTATED LIST OF THE SPECIES 97 
28. IMPARFINIS BOLIVIANUS Pearson 
Imparfinis bolivianus Pearson, 1924, Ind. Univ. Studies, no. 64, 12, pl. 11, fig. 3, Huachi, Bolivia; 
Pearson, 1937a, Proc. Cal. Acad. Sei., (4), XXIII, 92, Pusoc, Upper Maranon. 
Intercordilleran streams of eastern Peru and Bolivia 
Genus 12: PIRAMUTANA Bleeker 
Piramutana Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 99; 
Rigenmann and Higenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 186. 
Type: Bagrus piramuta Bleeker 
Amazon and tributaries 
Top of head and occipital processes granulated, covered with skin; occipital 
processes separated a little from dorsal plate; the teeth cardiform and forming an 
uninterrupted band on vomer and palatines; maxillary barbels flattened and band- 
like. 
29. PIRAMUTANA PIRAMUTA (Bleeker) 
Bagrus piramuta Wner, 1857, Sitzb. Kk. Akad. Wiss. Wien, X XVI, 382. 
Piramutana piramuta Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 99; 
Gunther, 1864, Cat. Fish. Brit. Mus., V, 111; 
Higenmann and Higenmann, 1890, Occ. Papers Cal. Acad. Sei., I, 186; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sci. Phila., XCI, 224, two, 233 and 248 mm., Con- 
tamana. 
The Amazon and its tributaries 
Genus 13: NANNORHAMDIA Regan 
Nannorhamdia Regan, 1913, Ann. Mag. Nat. Hist., (8) XII, 467; 
Eigenmann, 1922, Mem. Carnegie Mus., [X, 39. 
Type: Nannorhamdia spurrelli Regan 
Colombian streams to oriental Bolivia 
Closely allied to Rhamdia and especially to Chasmocranus, differing from the 
former in the much larger frontal fontanel and the large occipital fontanel, with 
the upper margin of the orbit free; differing from the latter in the narrower band of 
premaxillary teeth without the backward-projecting angle; the dorsal and pectoral 
spines much feebler than in Rhamdella. 
30. NANNORHAMDIA LONGICAUDA (Boulenger) 
Pimelodus longicauda Boulenger, 1887, Proc. Zool. Soc. London, 275, pl. xx, fig. 2, Canelos. 
Rhamdia longicauda Eigenmann and Kigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 126; 
Higenmann and Kigenmann, 1890, Oce. Papers Cal. Acad. Sei., I, 135; 
EKigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 386; 
Pearson, 1937a, Proc. Cal. Acad. Sci., (4), XXIII, 92, forty-one specimens from Paipay 
and Tingo de Pauea, upper Maranon. 
