148 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



Ambassus Swainson, Nat. Hist. Animals, vol. 2, 1839, p. (18,168) 20Q. 



Type Centropomus ambassis Lacepede. 

 Priopis (Kuhl and Van Hasselt) Valenciennes, Hist. Nat. Poiss., 



vol. 6, 1830, p. 378. Type Priopis argyrozona (Kuhl) Valenciennes, 



monotypic. 



Body well compressed, ovoid or oblong. Head large. Eye large, 

 little advanced. Mouth protractile, large. Maxillary exposed, with- 

 out supplemental bone. Teeth villiform, in bands in jaws, on vomer 

 and palatines and sometimes on tongue. Lower ridge and edge of 

 preopercle serrate. Opercle without conspicuous spine. Preorbital 

 edge serrate. Vertebrae 24 of which 14 caudal. Scales moderate 

 or large, 25 to 40, frequently deciduous. Cheeks and opercles scaly. 

 Dorsals divided by deep notch, spinous fin usually little higher or 

 second erect spine longest. First anal spine short, second and third 

 subequally long, usually longer than soft rays. Ventral below pectoral 

 base, with scaly basal flap. 



The species we include in this genus are all more or less similar in 

 both shape and coloration. They are all embraced in Bleeker's Atlas 

 except Ambassis nalua (Buchanan-Hamilton), which was not obtained 

 in the Albatross explorations. A number of nominal species have 

 been described in late years, chiefly from tropical Australia. 



ANALYSIS OF THE SPECIES 



a 1 . Ambassis. Scales 24 to 30 in lateral line to caudal base; cheek with 1 or 2 



rows of scales; second and third anal spines subequally long. 



b l . Predorsal scales 7 to 14; lateral line complete; eye more than 14 of head. 



c 1 . Depth 2}4 to 2Yb', eye 2 z /i to 2% in head; interopercle dentate; black 



terminal blotch on second, third and fourth spinous dorsal membranes; 



caudal uniformly pale kopsii 



c 2 . Depth 2% to 3; eye 3 to 33^ in head; interopercle smooth; second 

 spinous dorsal membrane entirely black; each caudal lobe darker 



medianly ur otaenia 



b 2 . Predorsal scales 14 to 20. 



d l . Lateral line complete; depth 2% to 2J^; eye 3 to 2> x /i in head; second 



spinous dorsal membrane dusky to blackish safgha 



d 2 . Lateral line interrupted; eye more than x /i of head. 



e 1 . Body deeper, depth 2 to 2}i; interopercle dentate; second spinous 



dorsal membrane blackish terminally interrupta 



e 2 . Body more slender, depth 2^ to 2%. 



p. Uniformly light or silvery, without black on fins buroensis 



p. Second spinous dorsal membrane variably blackish with age. 



gymnocephalus 

 d 3 . Lateral line complete; depth 2% to 3; second spinous dorsal mem- 

 brane dusky to black terminally batjanensis 



aa 2 . Whitleyia, new subgenus. Scales about 40 to 46 in lateral line to caudal 

 base; cheek with 7 rows of scales; second erect dorsal and anal spines 

 enlarged and prominent, former higher than soft dorsal wolffi 



Subgenus Ambassis Cuvier 



Scales large, 24 to 30 in lateral line to caudal base. Cheek with 1 

 or 2 rows of scales. Second and third anal spines subequally long. 



