190 FISHES OF WESTERN SOUTH AMERICA 
Genus 81: LASIANCISTRUS Regan 
Ancistrus (Lasiancistrus) Regan, 1904, Trans. Zool. Soc. London, XVII, 224, 237. 
Lasiancisirus Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 409. 
Type: Chaetostomus heteracanthus Giinther 
Peruvian Amazon to Panama 
Separated from Ancistrus, Parancistrus, and Pseudancistrus as follows (after 
Regan): with stoutish bristles on the interopercle where they have slender ones; 
sides of snout with or without short bristles, where the other genera are provided 
Fic. 22. Catching the candiru on split fish without the aid of tackle. 
with them; a few slender bristles outside the stouter ones. Resembling the other 
genera except Pseudancistrus in the retractile nature of the spines, withdrawing 
beneath the opercle. 
177. LASIANCISTRUS HETERACANTHUS (Giinther) 
Chaetostomus heteracanthus Giinther, 1869, Proc. Zool. Soc. London, 425, figs. 3 and 4, one, 73 inches, 
Bartlett, Peruvian Amazon. 
Hemiancistrus heteracanthus Eigenmann and Kigenmann, 1889, Proc. Cal. Acad. Sci., (2), II, 44; 
Eigenmann and Eigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 420. 
Ancistrus (Lasiancistrus) heteracanthus Regan, 1904, Trans. Zool. Soc. London, XVII, 224, 237. 
Lasiancistrus heteracanthus Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 409. 
