132 FISHES OF WESTERN SOUTH AMERICA 
Hemidoras natterert Eigenmann and EKigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 158; 
Eigenmann and Figenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 253; 
figenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 394; 
Fisher, 1917, Ann. Carnegie Mus., XI, 421. 
Trachydoras nattereri Kigenmann, 1925, Trans. Amer. Phil. Soc., XXII, 338, pl. xviii, figs. 1 and 2; 
pl. xxvi, figs. 2 and 3; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sci. Phila., XCI, 228, two, Contamana. 
Upper Amazon of Peru and Bolivia to Brazil 
15967, 1, 1830 mm., Iquitos, Morris, 1922. 
89. TRACHYDORAS ATRIPES Eigenmann 
Trachydoras atripes Eigenmann, 1925, Trans. Amer. Phil. Soc., XXII, 339, pl. ii, fig. 5; pl. xviii, 
figs. 6-8; pl. xxvi, fig. 4. 
Maranon to basin of Rio Mamoré 
15877, 1, type, 72 mm. over all, brook at Hacienda Ica, Rio Itaya, near Iquitos, Allen, September, 
1920. 
Specimens were collected by John Haseman in Bolivia. 
Genus 44: DORAS Lacépéde 
Doras Lacépéde, 1803, Hist. Nat. Poiss., V, 116, Stlurus carinatus and costatus Linnaeus; 
Bleeker, 1863, Nederl. Tijdsch. Dierk., I, 13, carinatus; 
Jordan, 1917, The Genera of Fishes, 65; 
Eigenmann, 1925, Trans. Amer. Phil. Soc., X XII, 340. 
Oxydoras Kner, 1855, Sitzb. KIx. Akad. Wiss. Wien, XVII, spp. 
Hemidoras Bleeker, 1858, Ichth. Arch. Indici., Siluri, stenopeltis ; 
Eigenmann and Higenmann, 1890, Oec. Papers Cal. Acad. Sei., I, 250. 
non Doras Giinther, Eigenmann and Eigenmann, ete. 
Type: Silurus carinatus Linnaeus 
Peru to Guianas and Bolivia 
The Eigenmann monograph of the Doradidae regards Doras as a polyphyletic 
group, or the residuum of the family after the several specialized genera have been 
removed. If the air bladder is of as great taxonomic value as indicated through- 
out the monograph, we do have several possible genera still accepted as Doras. 
This is a question which may hinge upon embryological studies of numerous species. 
Here as in many like situations systematic ichthyology halts for the lack of de- 
tailed studies in the field upon the life histories and biology of living fishes. 
Maxillary barbels fringed; bases of mental barbels united by a membrane; eye 
in posterior half of the head; adipose short and not continued as a low ridge; 
caudal forked; origin of the ventrals nearer the caudal than the snout; fontanel 
not prolonged into a groove; lateral scutes moderate, the first connecting the 
dorsal plate, the first rib, and the humeral process. Only one species recognized 
In our area. 
