466 PROCEEDINGS OF THE ACADEMY OF [Oct., 



those on body. Ventral with a small axillary scale. Lateral line, 

 incomplete, midway on side, starting from shoulder, of simple tubes, 

 and ending about 2 scales before origin of dorsal. 



Dorsal inserted well posterior or near last f in head and trunk, and 

 second ray evidently highest, others graduated down. Adipose fin 

 placed in last third of space between origin of dorsal and base of 

 caudal, and its length a little less than eye. Anal inserted behind 

 middle of base of dorsal, or nearer base of caudal than that of ventral, 

 and third ray longest, or others graduated down. Caudal forked, 

 lobes pointed. Pectoral reaching less than half way to ventral. 

 Ventral a little more than half way to anal. Vent close in front of 

 anal. 



Color in alcohol dull or pale brown, back a deeper shade than lower 

 surface. About 8 longitudinal darker streaks of brownish than general 

 body-color, those below paler. Head brown, lower surface paler. 

 Fins pale brown, dorsal and caudal perhaps a trifle darker. Base of 

 upper caudal lobe with its lower lobe marked with a jet-black blotch 

 a little larger than pupil. Iris pale brownish. 



Length about 11 inches (caudal damaged). 



Type, No. 16,642, A. N. S. P. Truando, Rio Atrato basin in the 

 Isthmus of Darien, Colombia. From the Smithsonian Institution 

 (No. 1,658). 



I am indebted to Mr. Barton A. Bean for the data concerning this 

 fish. According to him it approaches Xiphostoma hujeta Valenciennes, 

 a species very imperfectly described though, which it seems to resemble 

 so far as the original account permits. Provisionally at least it had 

 best be considered distinct. 



(Named for Mr. Barton A. Bean, Assistant Curator of Fishes, 

 United States National Museum.) 

 Hydrolycus peotoralis (Gunther). 



Hydrolycus pectoralis Cope, Proc. Amer. Philos. Soc. Phila., XVII, 1877-78 

 (May 17, 1878), p. 688. Peruvian Amazon. Prof. J. Orton. 



Head 4 to 4f ; depth 3^ to 3|; D. ii, 10; A. ii, 45, i usually, sometimes 

 varying to 43 or 46; scales usually 90 in lateral line to base of caudal; 

 snout 3^ to 4 J in head, measured from tip of upper jaw; eye, meas- 

 ured vertically, 2| to 3^; interorbital space 3f to 4|^; total length 5i to 

 8i inches. Six examples from collections of 1873 and 1877. 

 Hydrolycus soomberoides (Cuvier). 



Hydrolycus scomberoides Cope, Proc. Acad. Nat. Sci. Phila., 1871 (1872), p, 

 292. Between the mouth of the Rio Negro and the Peruvian Amazon or 

 Ucayale River. Robert Perkins. 



Head 4|; depth 3; D. ii, 10; A. ii, 40^ i; scales about 112 in lateral 



