FISHERY BULLETIN: VOL. 82, NO. 4 



the angular bears three large processes; the dor- 

 sal process directed forward and upward, the ven- 

 tral process directed forward, and the posterior 

 process directed backward and upward. This pro- 

 cess is hooked and carries a transverse articular 

 facet for the quadrate. Between the dorsal and 

 ventral processes is Meckel's cartilage which ex- 

 tends directly anterior into the space between the 

 two arms of the dentary. The length of the angu- 

 lar to the tip of the dorsal process is 31-42% of the 

 total length of the bone; the length to tip of the 

 ventral process is 42-53% of the total length. The 

 maximum width of the angular, measured from 

 the tip of the dorsal process to the tip of the 

 ventral process is 34-43% of the total length. 

 Devaraj (1977) stated that the ventral process 

 was longer and narrower in S. commerson and 

 Acanthocybium than in other Indian species 

 and we confirm this. The ventral process is as 

 long or longer than the dorsal process in S. 

 commerson (ventral process 99-162% of the dorsal 

 process), Acanthocybium (99-148%), and also in 

 S. queenslandicus (115-136%). The next longest 

 ventral processes are in S. cavalla (80-104%) and 

 S. sinensis (82-97%). The other 14 species of 

 Scomberomorus (and Grammatorcynus) have 

 shorter ventral processes, 40-85% of the length of 

 the dorsal process. The shortest ventral process is 

 in S. regalis, 40-44%. 



Retroarticular. — The retroarticular bone (fre- 

 quently called angular) is rhomboid and attached 

 firmly, but not fused to the posteroventral mar- 

 gin of the angular (Fig. 25). No differences were 

 found among the retroarticulars of the species of 

 Scomberomorus. 



PALATINE ARCH.— The palatine arch con- 

 sists of four pairs of bones in the roof of the 

 mouth: palatine, ectopterygoid, entopterygoid, 

 and metapterygoid. 



Palatine. — The palatine (Fig. 26) is forked 

 both posteriorly and anterolateral^. The dorsal 

 branch of the anterolateral fork is hooked, and 

 its anterior end articulates with a facet on the 

 maxilla, immediately ventral to the nasal. The 

 ventral branch is cone-shaped or pointed. The 

 exterior branch of the posterior fork carries on its 

 dorsal surface the shank of the ectopterygoid, and 

 the inner, flat, thin branch is attached to the 

 anterior end of the entopterygoid. The lateral 

 aspect of the palatine is roughly triangular and 

 concave, and closely attached to the mesial wall 

 of the maxilla. Grammatorcynus (Fig. 26d) differs 

 from Scomberomorus (Fig. 26a, b) and Acantho- 

 cybium (Fig. 26c) in almost lacking the anteriorly 

 directed ventral branch. Acanthocybium has a 

 distinct ventral branch but it is shorter than the 



a 



FIGURE 26. — Left palatines in lateral view, slightly rotated to better show tooth patch, a. Scomberomorus semifasciatus , 

 New Guinea, 740 mm FL, 2 x . b. Scomberomorus commerson , New South Wales, 1,155 mm FL, lx. c. Acanthocybium 

 solandri, Miami, Fla., 1,403 mm FL, lx . d. Grammatorcynus bilineatus, Timor Sea, 453 mm FL, 2x . 



580 



