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Show 189 J.] SILUROID FISHES FROM BRAZIL. 235 16. BUNOCEPHALUS IHERINGII, sp. n. (Plate XXVI. fig. 2.) D. 5.1 A. 9. P. 1/4. V. 6. Head much depressed, its depth twice in its width, once and one third in its length ; upper jaw not projecting ; cranial ridges feebly prominent; interorbital space concave, one third the width of the corresponding part of the head; maxillary barbel extending a little beyond the base of the pectoral; mental barbel half as long as and not reaching to postmental. Pectoral spine slightly curved, the terminal hooks largest; coracoid process slightly divergent, extending to middle of pectoral spine and beyond humeral process. Dorsal fin nearer the end of the snout than to the caudal. Hind portion of the tail compressed. The length of the caudal fin contained abu t five times in the total length. Skin everywhere covered with small warts. Dark brown above; a blackish lateral stripe, with small greyish spots; greyish white below. Total length 60 millim. Two specimens. The only other described species with 9 anal rays, B. aleuropsis, Cope, from Pebas, Ecuador, differs in the longer maxillary barbel, which is said to reach the middle of the pectoral spine. The discovery of this new species extends the range of Bunocephalus considerably southwards. 17. TRICHOMYCTERUS BRASILIENSIS, Ltitk. 18. TRICHOMYCTERUS MINUTUS, sp. n. (Plate XXVI. fig. 3.) D. 8. A. 6. Length of head two ninths of the total (without caudal); eye a little nearer the end of the suout than to the opercular border, measuring two thirds the interorbital width ; gill-opening not continued forward to below the eye ; maxillary barbels three fifths the length of the head, not reaching the gill-opening; nasal barbels short, extending to the eye. Dorsal fin entirely in front of anal; none of the fin-rays prolonged ; the origin of the dorsal midway between the end of the snout and the extremity of the caudal. Caudal fin rounded. Pale brown above, with three longitudinal series of large squarish dark brown blotches ; fins immaculate. Three specimens from the San Lorenzo district. The largest measures only 40 millim. EXPLANATION OF THE PLATES. PLATE XXV. Fig. 1. Pimelodus (Pimelodella) nigribarbis, Blgr. 2. Pimelodus (Pseudopimelodus) cottoides, Blgr. 3. Otocinclus nigricauda, Blgr. P L A T E XXVI. Fig. 1. Chcetostomus cirrhosus, Val. Upper views of heads of male and female. 2. Bunocephalus iheringii, Blgr. 3. Trichomycterus minutus, Blgr. 1 The last ray is adnate. |