156 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



A?nbassis macracanthus (not Bleeker) Day, Proc. Zool. Soc. London, 1870, 



p. 681 (Andamans and estuaries). 

 Ambassis interrupta var. reticulatus Weber, Nova Guinea, vol. 9, pt. 4, 



1913, p. 574. Merauke, Bivak Island, Sabang, Alkmaar, Rivierkamp, 



Verlaten Bocht. 



Depth 2% to 2Y b ) head 2% to 2%, width 2% to 2%. Snout 43/g 

 to ±% in head from snout tip; eye 2% to 3, greater than snout or 

 interorbital; maxillary reaches front eye edge or but slightly beyond, 

 expansion Z% to 5 in eye, length 2% to 2% in head from snout tip; 

 teeth villiform, small, in narrow bands in jaws, on vomer and palatines 

 and narrow median row or band on tongue; interorbital 33^ to 4^2, 

 very slightly convex; single postero-supraorbital spine, none below; 

 preorbital edge with 6 or 7 spines, ridge with few weaker serrae; 

 lower edge and ridge of preopercle serrate, upper ridge and edge 

 entire, also slightly enlarged spine at angle of ridge. Gill rakers 

 8 + 22, slender, lanceolate, much longer than gill filaments or 2 in eye. 



Scales 10 or 11 + 11+4 or 5, of which last on caudal base, lateral 

 line interrupted; 3 scales above lateral line, 8 below, 14 predorsal 

 nearly midway in interorbital form median keel, 2 rows on cheek and 

 preopercle flange naked; caudal with fine scales basally; basal scaly 

 sheaths, one scale wide along dorsals and anals. Scales with 8 or 9 

 basal radiating striae and 4 or 5 incomplete auxiliaries; circuli fine. 



D. VII, I, 9, i, second erect spine \ x /% to \yi in total head length, 

 first ray 1% to 2; A. Ill, 9, i, second spine \% to 2, often third spine 

 longer; caudal lKo to 1}4, deeply forked, slender lobes sharply pointed; 

 least depth of caudal peduncle 2% to 2J^; pectoral 1^ to l}i; 

 ventral V/ z to 1%. 



Pale brown generally, scales on back and upper surfaces dusted 

 with darker brown dots, on back as broad darker marginal areas. 

 Sides and lower surfaces with bright silvery white tints. Median 

 diffuse silvery white band from eye to caudal. Fins all pale or with 

 grayish dusting terminally on verticals. Membrane between second 

 and third dorsal spines dusky to blackish. Iris silvery white. 



Andamans, East Indies, and Philippines. Bleeker reports 24 

 examples with the largest 120 mm. long, which is much greater than 

 any of our material. 



Five examples. Alimango River, Alimango Bay, Burias Island. March 5, 1909. 



Length 70 to 92 mm. 

 Fifteen examples. Camp Overton, Iligan Bay, Mindanao. August 6, 1909. 



Length 63 to S3 mm. 

 12831. Cavite and San Roque markets. June 27, 1908. Length 92 mm. 

 Four examples. Chase Head, Palawan Island. December 22, 1908. Length 



30 to 58 mm. 

 Three examples. Damphlit, Malabon. August 10, 1908. Length 46 to 74 mm. 

 Thirty-two examples. Dumara River. February 25, 1909. Length 50 to 



82 mm. 



