CARANGIDAE 45 



with age. They are large in all ages, and the base of the skull is ex- 

 panded to accommodate them. 



Three basibranchials are present in all genera, the first in front 

 of the hypobranchials of the first arch and hooking under the glosso- 

 hyal, as in the family Scombridas. The hypobranchials of the fourth 

 arch are missing, as they almost universally are in bony fishes. 



There is nothing remarkable about the hyoid arch. All of the 

 usual elements are present: a glossohyal and urohyal, two hypohyals on 

 each side and a cerato, epi and interhyal. The urohyal bears a longi- 

 tudinal wing of bone along its lower edge on each side, and the cerato- 

 hyal is pierced by a large foramen near its upper edge. 



The Shoulder and Pelvic Girdles. 



The shoulder girdle shows scarcely any departure from the typical 

 acanthopteroid arrangement. The pectoral is not placed so near the 

 level of the top of the clavicle as in the Scombridae, and the clavicle 

 does not slope so far forward below it, being more nearly vertical. 

 Elagatis, Seriola, Naucrates, Oligoplites and Scomberoides approach the 

 condition of the Scombridae in this respect more nearly than the others 

 do, though not very nearly. The clavicle ends above in a point, over 

 which the supraclavicle articulates. Below the point and just above 

 the actinosts a broad, rounded wing is sent back for the support of 

 the postclavicle. 



The postclavicle is in two parts, an upper wide, thin bone and a 

 lower long, narrow bone, sometimes long and slender like a typical 

 fish rib. 



A large foramen is entirely contained by the hypercoracoid, but 

 either the clavicle or the hypocoracoid may send a lamina of bone to 

 its border on the outer surface of the girdle. 



The suture between the hypo and hypercoracoids usually ends be- 

 tween the third and fourth actinosts from the top, but it may vary 

 from the middle of the third to the middle of the fourth, so that 2^ 

 to 31/2 of the 4 actinosts are supported by the hypercoracoid. 



The hyyocoracoid arches away from the clavicle and nearly, or 

 quite, meets it again at its lower end. The clavicle never projects far 

 beyond the lower end of the hypocoracoid as in many of the Scom- 

 bridae. 



A large supraclavicle is always present. The posttemporal is 

 widely forked except in Trachinotus. The upper fork broadly overlies 

 the epiotic, and is a little more firmly attached than is usual. It often 



