1919.] NATURAL SCIENCES OF PHILADELPHIA. 9 



edges entire, and head behind front eye edge about 3 in its length. 

 Nasal cavity about f of pupil, superior. Interorbital flattened. 



Gill-opening extends forward about opposite front pupil edge. 

 Gill-rakers 5+11, lanceolate, longest about f of filaments and 

 latter 2| in eye. Isthmus narrow slender frenum. 



Scales moderately large, cycloid, rather narrowly imbricated, 

 basal striae 4 to 6, basal circuli 35 to 40 and terminal faces entire. 

 Head scaly, a single row of large scales on cheek, and scales on 

 opercles large. Several rows of small scales on caudal base, and 

 dorsal and anal apparently without scales. Lateral line com- 

 plete, low along side, and extends up behind just below median 

 scale at caudal base, all tubes simple. 



Dorsal inserted at last fourth between hind edge of gill-opening 

 and caudal base, last ray reaching back little beyond latter. Anal 

 inserted trifle behind dorsal origin, much shorter than dorsal. 

 Caudal rounded behind. Pectoral placed high, small. Ventral 

 inserted scarcely before last third in space between hind edge of 

 gill-opening and caudal base, fins not quite half way to anal. Vent 

 close before anal. 



Color in alcohol pale, dull brownish generally, more or less uni- 

 form. Sides of head and below with traces of silvery reflections. 

 A narrow silvery-gray lateral band, about wide as pupil, most 

 conspicuous between dorsal and anal. 



Length 142 mm. 



Type, Xo. 7,584, A N. S. P. Japan. Dr. A. A. Henderson. 



This species, known only from the type described above, is 

 closely related to Zenarchopterus amhlyurus (Bleeker). According 

 to Bleeker 's figure*', it differs in the more posterior insertion of 

 the ventral, shorter row of lower teeth, apparently more rounded 

 caudal and scaleless dorsal fin. This specimen has long been in 

 the Academy, probably sixty years or more, and still has the 

 original labels intact. 



(Named for Dr. A. A. Henderson.) 



Zenarchopterus philippinus (Peters). 

 Philippines. 



Zenarchopterus dispar (Valenciennes). 

 Philippines. 



6 Atlas Ichth., VI, 1866-72, p. 61, Pi. 4, fig. 1. 



