164 FISHES OF WESTERN SOUTH AMERICA 
Naked catfishes with inferior mouth; lower lip much expanded and reverted; 
teeth bicuspid, in a narrow band in each jaw; gill-membranes broadly united with 
the isthmus; anterior and posterior nares closely approximated; maxillary barbels 
present, no mental or nasal barbels. Dorsal vertically placed above the ventrals; 
air bladder enclosed within Weberian apparatus forward, with a bony diaphragm. 
For reasons given below the genera Cycloptum, Arges, Brontes, and Styogenes, 
once considered members of a family Argiidae, are here synonyms of Astroblepus. 
Genus 64: ASTROBLEPUS Humboldt 
Astroblepus Humboldt, 1806, Rec. d’Obs. Zool. Anat., I, 19; 
‘igenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 417; 
Eigenmann, 1922, Mem. Carnegie Mus., EX, 51. 
Cyclopium Swainson, 1839, Nat. Hist. Fish., IT, 3065. 
Arges Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 333, pl. 444; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 222; 
Regan, 1904, Trans. Zool. Soc. London, XVII, 307. 
Brontes Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 341, pl. 445. 
Styogenes Giinther, 1864, Cat. Fish. Brit. Mus., V, 223, humboldtit. 
Type: Astroblepus grixalvii Humboldt 
The Andean highlands from Colombia to Peru 
Cabezon, colloquial name in allusion to large head. 
Adipose fin short, near caudal, with a short spine; teeth small, the mandibulars 
and inner intermaxillaries broadened and notched at the tips; eyes small and 
upturned. 
One of the most successfully formed of all groups of fishes for climbing; lips 
flattened and suctorial; paired fins set so as to inch forward or backward in opposi- 
tion to swift currents; gills so adapted as to valve water inward at the tops of the 
gill opening and to exhale at the bottom while using the mouth as a holdfast. 
The Eigenmanns (1890) expressed doubt that the Humboldt genus A stroblepus 
should be placed with the genera Arges, Cyclopium, and Brontes in Gill’s family 
Argiidae, on account of the supposed lack of ventral fins. Meanwhile the many 
years’ collecting of the Carnegie Museum and Indiana University expeditions have 
brought to light no specimens without ventrals. This seems to justify (Higenmann, 
1922 b) relegating the above genera to the synonomy of Astroblepus Humboldt. 
128. ASTROBLEPUS SABALO (Cuvier and Valenciennes) 
Arges sabalo Cuvier and Valenciennes, 1840, Hist. Nat. Poiss., XV, 335, pl. 444, Santa Ana; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 222; 
Steindachner, 1875, Sitzb. Kix. Akad. Wiss. Wien, LX. XII, 48, Tulumayo; 
Steindachner, 1876, Sitzb. IKXI<. Akad. Wiss. Wien, LX XII, 598; 
Cope, 1878, Proc. Amer. Phil. Soe., XVII, 681, seven, R. Urubamba; 
Steindachner, 1879, Denkseh. Kix. Akad. Wiss. Wien, XLI, 23; 
Steindachner, 1882 (1883), Denksch. KIX. Akad. Wiss. Wien, IV, 17, pl. iv, fig. 2 and 2b, 
Rio Huambo; 
