NATURAL SCIENCES OP PHILADELPHIA. 431 



I. Lateral line behind straight and even with the axis. 



A. Lateral line more or less protected by larger plates.... Caran<jin.s:. 

 B. Body oblong or elongated; spinous dorsal developed. 

 C. Body perfectly fusiform ; snout above axis, 



1. Spurious dorsal (1) and anal (1) Unlets Decapterus. 



2. Spurious finlets none Trachurops. 



CC. Body unequally developed with regard to axis, 



the dorso-rostral outline being disproportion- 

 ately decurved. 

 a. Head moderate ; suborbital bones moderately 

 elevated (=eye) ; teeth of jaws enlarged in 

 outer row. 

 Body subfusiform ; canine teeth none in front 



of lower jaw Paratractus. 



Body oblong ; canine teeth (2) in front of lower 



jaw Carangus. 



/?. Head small; suborbital bones very low ; teeth 



of jaws villiform Carangops. 



BB. Body rhomboid ; spinous dorsal rudimentary in 



adult Blepharichthys. 



AA. Lateral line unarmed. 

 B. Body exceedingly compressed and elevated ; profile 



very oblique or subvertical VomeriinjE. 



et. Body oblong ; abdominal outline very convex in 



youth; dorsal and anal fins nearly uniform Vomer. 



0. Body obliquely elevated, pentagonal ; dorsal and 

 anal fins falciform. 



1. Ventral fins very short Selene. 



2. Ventral fins very long Argyriosus. 



BB. Body much compressed, with the inferior outline 



trenchant ; profile oblique and rectilinear ; anus 



behind ventral fins ChxoroscombkinjE. 



Chloroscombrus. 

 BBB. Body less compressed, with the abdomen trans- 

 versely convex. Anus submedian or poste- 

 rior. 

 *. Abdomen considerably shorter than the anal fin, 



which nearly equals the second dorsal Trachvnotin.e. 



Trachynotus. 

 tf. Abdomen nearly equal to the anal fin, which is 



much shorter than the second dorsal Centronotin;e. 



Spinous dorsal represented by short and free spines 



in adult Naucrates. 



Spinous dorsal well developed. 



Head high Zonichthys. 



Head oblong Halatractus. 



II. Lateral line behind scarcely straight or even with the 



axis, but rather above Pomatomho?. 



C ARAN GIN jE (Bon.) Gill. 

 Genus DECAPTERUS Bleeker. 



DECAPTERUS PUNCTATITS Gill. 



Scomber hippos Mltchill (nee Linn,). 

 Caranx punctatus Agassiz, Cuv. et Vol. 



This species appears to be a very rare and occasional straggler to the Northern 

 1862.] 



