basibranchials 



epibranchials 

 pharyngobranchials 



iterhyal hi 



epihyal 



hypobranchials 

 ceratobranchials 

 urohyal 



dorsal hypohyal 



Figure 3S.—Triacanthiu biaculeatut: 



lateral (left) and anterior (right) views 



of first two dorsal spines (erected), 



with basal pterygiophore shown in lateral 



view in both cases, 1 13 mm SL, Borneo. 



Figure 37 .—Tripodichthys angustifrona: 

 dorsal view of branchial arches (extended 



on lower side); lateral view of hyoid 

 arch and urohyal; 137 mm SL, Australia. 



Figure 39.— A, Parahollardia lineata, 45.7 mm SL, 



Florida, and B, Triacanthus biaculeatus, 



SL, Borneo: lateral views of pelvis 



and pelvic fin in place (above) and of 



pelvis with pelvic fin removed (middle); 



anterior views of the base of the pelvic spine (below), 



show the structural differences in the locking 



mechanism of the Triacanthodidae (indefinite 



number of positions of erection) and 



Triacanthidae (two positions of erection). 



