Jordan and Evermann. — Fishes of North America. 939 



428. TRACHINOTUS,* Lacepede. 

 (Pampanos.) 



JracSdnolus, LACfipfiDE, Hist. Nat. Poiss., in, 79, 1802, {folcatiis). 

 desiomoi'iif, LAcf;PKnE, Hist. Nat. Poiss., in, 95, 1802, {hlochii). 

 Acatilhinioii, LacIcI'KDE, Hist. Nat. Poiss., iv, 500, 1803, {rhnmhoidef). 

 Bnthrolxmm, Hor.nROOK, Ich. South Carolina, 82, 18G0, {pampamis). 

 Dnliodini, GiRARii, Proc. Ac. Nat. Soi. Pliila., 1858, lfi8, {nmiUiins). 



Body compressed, moderately elevated, tlio general outliue ovate. 

 Caudal peduncle short and rather slender. Abdomen not trenchant, 

 shorter than the anal fin. Head moderately compressed, very blunt, the 

 snout abruptly truncate. Mouth nearly horizontal, the maxillary reach- 

 ing the middle of the eye; premaxillaries protractile; maxillary vs'ithont 

 distinct supplemental bone. Jaws, vomer, and palatines with bands of 

 villiform teeth, which are deciduous Avith age. Preopercle entire in the 

 adult. Gill rakers short. Gill membranes considerably united. Spinous 

 dorsal represented by 6 rather low spines, which are connected by mem- 

 brane in the young but are free in the adult. In old specimens the spines 

 appear small on account of encroachments of the flesh, and ultimately 

 often disappear. Second dorsal long, elevated in front ; anal opposite to 

 it and similar in form and size : 2 stout, nearly free spines in front of 

 anal, and 1 connected with the fin, these often disappearing with age. 

 Scales small, smooth. Lateral line unarmed, little arclied ; no caudal 

 keel. " When extremely young the preoperculum is armed at the angle 

 with 3 large spines, and smaller ones above and below. The spinous 

 dorsal is developed as a perfect fin, and teeth are present on the jaws and 

 palatine arch. In this stage the species has never been described by pre- 

 vious naturalists, and consequently has received no name, as the cor- 

 responding stage of Xaucrates (Xauclerns) has. At an early period the 

 preopercular spines are absorbed into the substance of the preoperculum 

 and disappear. The spinous dorsal and the teeth are still retained. In 

 this condition it remains for some time, the spinous dorsal, however, 

 gradually losing its relative size, while the soft vertical fins increase. 

 In this stage the species belongs to the genus DoJiodon of Girard. At a 

 later period the membrane connecting the dorsal spines has become obso- 

 lete, and the species then represents the genus Traehynotus, as understood 

 by Cuvier & Valenciennes, and others. Finally, in old age, the teeth of 

 the jaws, palate, and pharyngeal bones have fallen out, and the lobes of 

 the dorsal, anal, and caudal fins attain their greatest extension and 

 become pointed. This final stage has been made known by Holbrook 

 under the new generic name of Bothrola'mus" {(JiiW, Proc. Ac. Nat. Sci. 

 Phila., 1862, 440). The pseudobranchia^ also disappear in old specimens. 

 Some of the species of Truchinotus (caroli mis, etc.) are among the most 

 highly valued of our food-fishes. Most or them are, however, not of 

 superior quality, (rpaxix, rough; vurni;, back; hence properly written 

 Trachyiiotus ) 



* For a review of the species of Trachinotus, see Meek & Goss, Proc. Ac. Nat. Sci. Phila., 1884, 

 121. 



