30 OSTEOLOGY OP SCOMBROID FISHES 



session of finlets, and should perhaps be included in this subfamily, or 

 else these two genera might be considered together as a separate sub- 

 family characterized by the possession of finlets. 



All of the other forms considered, except Traclvinotus, are here 

 included under the Caranginae. It is even less satisfactory to try to 

 divide them than in the case of the others, and though Selene is not 

 nearly so closely related to Trachyurops for instance as some forms 

 are to each other that are here arranged in different subfamilies, there 

 is no place to draw a dividing line. There seems no good reason for 

 recognizing the Chloroscombrinae. 



The Caranginae may be characterized by the strong first interhaemal 

 process firmly united with the strong first haemal process and together 

 forming a long curved brace bordering the abdominal cavity behind, 

 as in the flounders. In Decapterus, Trachurops and Trachurus this 

 character is not so well marked as in the others, and it is a character 

 of all of the Carangidae except the Naucratinae. The Caranginae have 

 the lateral line abruptly arched in front, and usually armed with 

 keeled plates, and there are usually two detached spines in front of the 

 anal. 



The Trachinotinae contains only the genus Trachinotits and is a 

 well defined subfamily. It is placed at the end of the series, as it has 

 no characters to show from where it may have branched from the other 

 Carangoids. 



It is characterized by having the snout region shortened; the max- 

 illary without a supplemental bone; the posttemporal but little forked; 

 the opisthotic separating the exoccipital from the pterotic to a greater 

 extent than in the other genera; the pharyngeals enormously developed, 

 with the parasphenoid expanded to accommodate the superior ones; and 

 with the posterior opening to the myodome reduced to a pore or obso- 

 lete. 



DIAGNOSIS OF CHARACTERS. 



Supraoccipital crest carried forward to ethmoid by the frontals. 

 Supraoccipital variously separating epiotics, or not at all, as viewed 

 from within the cranium. 



Exoccipitals meeting above and below, always for their full length 

 above, and broadly below, or in most cases for their full length. Pre- 

 f rentals broadly meeting at the median line; each pierced for the 

 passage of the olfactory nerve. 



