538 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



The color, darker in general than in most species of the subgenus, 

 is purplish brown, becoming darker below the first dorsal fin; bluish 

 black on the belly, chin, and opercles; and brownish black about the 

 occiput. The lower sides of the trunk and the median strip of the 

 tail are silvery, as are also the sides of the head. The upper parts of 

 the head and the snout are translucent ; the front margin of the snout 

 is black; the inner wall of the suborbital cavity is dark ventrally. 

 The roof of the buccal cavity is mainly silvery; the branchial cavity 

 is lined with white, for the most part, but with black posteriorly on 

 its outer sides (leaving the extreme rim of the branchiostegal and 

 opercular membranes white) ; the parietal peritoneum is blackish, but 

 underlain by silvery. The first dorsal fin is dusky, the anal lighter; 

 the paired fins are light and clear, but with a black base which is pre- 

 ceded ventrally b} 7 an area with metallic luster; the base of each ray 

 in the second dorsal and anal fins is marked by a black spot. 



The striations are not so widely developed as in striati-ssimus, 

 longiceps, lemgipes, and certain other species. The striated area ex- 

 tends backward from the ventral base about half way to the anus, 

 and forward, from above the ventral base, along the sides of the 

 isthmus. The striations are obsolete on and just below the pectoral 

 base, immediately anterior to the ventral bases, and on the gular 

 membrane, which, however, is crossed by the usual black lines not 

 similar to the true " striae." 



Table of measurements in hundredths of length to anus. 



1 A pseudocaudal developed. 



(nascens, being born, applied to this form to designate it as an in- 

 cipient species.) 



