5a. Second dorsal spines produced into a filament; mandibulary profile strongly concavo: distance of dorsal from end of snout equal to dopth, 2.0-2.50 head …………..G. punctatus
5b. Second dorsal spine not produced, as lung half depth body or somewhat longer; mondibuiary profile atraight or nearly so; distance of dorsal from end of snout longer than depth of body............................................6
6a. Scales in lateral line 46-48; head about equal to depth of body……………………….. G. oblongus
6b. Scales in lateral line 40-42............................ 7
7a. Scales in lateral line 40; head 4.1 in length…………………….G.setifer
7b. Scales in line 42; head 3.0 3.5 in length………………………………… G.macrosoma
Genus Pontoprion
A single spocies found in Thai water: Pentnurion longinnnus(Cantor).