FISHES OF THE FAMILY LORICARIID. 311 
ray 23-25 times in the total length, from base of last anal ray to the caudal 
d{-6} times. Body spotted or marbled with blackish ; dorsal and caudal with some 
dark spots on the rays. 
Total length 85 mm. 
Hight specimens from Colombia. 
4, ARGES CYCLOPUM. 
Pimelodus cyclopum Humboldt, Obs. Zool. i. p. 21, pl. vi. (1805). 
Cyclopium humboldtii Swainson, Nat. Hist. Fish. ii. p. 305 (1839). 
lrges cyclopum Cuv. & Val. Hist. Nat. Poiss. xv. p. 840 (1840). 
Stygogenes humboldtii Giinth. Cat. Fish. v. p. 223 (1864). 
Stygogenes cyclopum Giinth. t. c. p. 224. 
Length of head nearly 4 times in the total length. Interocular width equal to the 
distance from eye to posterior nostril, 8} times in the length of head. Teeth of the 
outer series of the premaxillaries mostly unicuspid; mandibulary teeth bicuspid ; 
barbel extending to gill-opening. First dorsal ray equal to 5 the length of head ; 
pectoral spine extending to middle of ventral; ventrals originating below the first 
dorsal ray, extending to the anal opening. Spine of adipose fin fairly well developed, 
freely movable, inserted at a distance from the caudal equal to 2 the length of the 
middle rays of that fin. Adipose fin represented by a membrane connecting the spine 
posteriorly to the caudal peduncle. Distance from tip of snout to base of first dorsal 
ray 23-25 times in the total length, from base of last anal ray to caudal 42 times. 
Body spotted or marbled with dark brown; caudal dark at the base and in its 
posterior half. 
Total length 45 mm. 
Four specimens from Madame Ida Pfeiffer’s collection, locality unknown, agree fairly 
well with Humboldt’s figure and may be provisionally referred to this species, which 
certainly belongs to the section with short adipose fin and movable spine. 
A. cyclopum was originally recorded from the Andes above Quito, Ecuador. 
5. ARGES WHYMPERI, 
Arges whymperi (part.) Bouleng. Proc. Zool. Soc. 1890, p. 451, pl. xli. fig. 2. 
Length of head 43 times in the total length. Interocular width nearly equal to the 
distance from eye to posterior nostril, 3{ times in the length of head. ‘Teeth of the 
outer series of the premaxillaries mostly unicuspid ; mandibulary teeth bicuspid; 
barbel extending $ of the distance from its base to the gill-opening. First dorsal ray 
equal to } the length of head; pectoral spine extending to anterior } of ventral ; 
ventrals originating nearly below the first dorsal ray, extending 3 of the distance from 
their base to the anal opening, which is situated at 7 of the distance from the base of 
VOL. XViI.— Part m1. No. 16.—October, 1904. 20 
