Excerpt from The Pygidiidae, a Family of South American CatfishesHead ¿at rounded, eyes small, superior, covered by the skin. Head times in length to basis of caudal fin. Depth at D. I. One-half length to basis pectoral fin, width of head two-thirds the same dis tance. Inter-orbital width times in length of head. Maxillary and external mental barbels extending beyond basis of pectoral, inner mental barbel one-half the same. Radii D. 7, P. 8, V. 6, A. 11, caudal acuminate. Skin entirely smooth.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.