134 FISHES OF WESTERN SOUTH AMERICA 
Known from the types taken at Iquitos. 
15962, 2, 77 and 147 mm., the latter the type, Iquitos, Morris, 1922. 
Named for Percival Morris, the Barbado-Peruvian who assisted in making the 
collections in the vicinity of Iquitos, and continued collecting for more than a year 
thereafter, following my departure. 
Genus 46: OPSODORAS Eigenmann 
Opsodoras Eigenmann, 1925, Trans. Amer. Phil. Soc., XXII, 348. 
Type: Opsodoras orthacanthus Eigenmann 
Amazon basin to the Guianas 
Back without scutes; origin of ventrals nearer caudal than snout; adipose not 
continued forward as a keel; mental barbels with a double series of barblets; a 
foramen on each side of the nuchal shield. 
Air bladder single, usually with filamentous, branched diverticula. 
93. OPSODORAS HEMIPELTIS Eigenmann 
Opsodoras hemipeltis Figenmann, 1925, Trans. Amer. Phil. Soc., X XII, 349, pl. xix, fig. 2; pl. xxiv, 
fig. 6. 
Kknown only from the type at the California Academy Museum. 
15879, 1, type, 148 mm., Rio Ucayah, Contamana, Allen, July, 1920. 
Noteworthy for its spindle form among its extreme relatives. 
94. OPpSODORAS PARALLELUS Eigenmann 
Opsodoras parallelus Kigenmann, 1925, Trans. Amer. Phil. Soc., X XII, 350, pl. xix, fig. 3; pl. xxi, 
fig. 3. 
Known only from the type from Iquitos in the Museum of the California 
Academy of Sciences. 
15964, 1, type, 151 mm., Iquitos, Morris, 1922. 
Closely allied to O. hemipeltis, if distinct from it. Differing in the better 
development of the lateral scutes, 0 + 32; top of head and nasals granular, opercle 
striate; maxillary barbel reaching beyond the eye; pectoral spines not reaching 
ventrals, with serrae on both surfaces of the spine. 
95. OpsopORAS HUMERALIS (IXner) 
Doras humeralis Wner, 1855, Sitzb. KK. Akad. Wiss. Wien, X VIT, 140, pl. iv, fig. 6, Rio Negro. 
Oxydoras humeralis Ginther, 1864, Cat. Fish. Brit. Mus., V, 206. 
Hemidoras humeralis Eigenmann and Eigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 158; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 258; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 394. 
