1891.] SIL.UROID FISHES FROM BRAZIL. 235 



16. BuNOCEPHALus iHERiNGii, sp. n. (Plate XXVI. fig. 2.) 



D. 5.' 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 about 

 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, Liitk. 



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, mea- 

 suring 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 fi^n 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) nigriharbis, Blgr. 



2. Pimelodus (Pseudopimelodus) cottoides, Blgr. 



3. Otocinclus nigricauda, Blgr. 



Plate XXVL 

 Fig. 1. Chcetostomus cirrhosus, Val. Upper views of heads of male and female. 



2. Bunoccphalus iherinqii, Blgr. 



3. Trichomycterus minutus, Blgr. 



} The la.st ray is adriate. 



