Pearson: Fishes of the Rio Beni Basin 11 
Rhamdia quelen (Quoy & Gaimard) . 
17045, 15, 92-135 mm., Tumupasa. Dec., 1921. 
17046, 18, 20-190 mm., Lake Rogoagua. Oct., 1921. 
17227, 4, 36-52 mm., Espia. July, 1921. 
Rhamdia micayi Eigenmann MS. 
17272, 6, 145-165 mm., Fopoi River, Upper Beni. Sept., 1921. 
17273, 5, 72-150 mm., Rio Colorado, Lower Bopi. Sept., 1921. 
17274, 5, 85-165 mm., dried during shipment, Espia. July, 1921. 
Nannorhamdia guttatus Pearson, sp. nov. Plate II, figs. 1 and 2. 
17268, type and paratypes, the largest the type, 110, 52, and 45 mm., 
Popoi River, Upper Beni. Sept., 1921. 
Head 4 4/5; depth 6; D. 7; A. 12; width of head 1.4 in its 
length; eye 6 in the head, interocular 3.75, snout 2.4; upper 
part of eye, in the type, with a free orbital margin, the lower 
part without a free orbital margin; the paratypes are entirely 
without a free orbital margin ; the fontanel extends to the base 
of the occipital process, which is covered by a thick skin ; 
mouth subterminal, exposing a part of the band of premaxil- 
lary teeth ; maxillary barbels extending to the base of the ven- 
tral in the type, in the smaller paratypes to the middle of the 
ventrals or slightly beyond; postmentals to the base of the 
pectorals in the type, to the end of the pectorals in the para- 
types; distance of the dorsal from the snout 2.8 in the total 
length; first pectoral ray prolonged, the spine 2 times in the 
length of the head; the first ray of the ventrals shorter than 
the second; caudal deeply forked, the lobes of about equal 
length, li/ 2 times longer than the head ; adipose fin 5 times in 
the total length. 
Color dark brown ; in life purplish ; a large dark spot on the 
supraoccipital ; a dark spot just behind the gill-opening ; four 
dark spots on the back, not extending on the sides, the first 
spot 1/3 of the distance between the posterior part of the 
head and the dorsal, the second just in front of the dorsal, 
the third thru the posterior half of the dorsal, the fourth 
just anterior to half the distance between the dorsal and the 
adipose ; in addition to these spots the young have three spots 
along the sides, one below the dorsal, one below the anterior 
part of the adipose, and one below the posterior part of the 
adipose; the lower caudal lobe darker than the upper; all the 
3—30279 
