524 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



portion of the head ; the outer ventral ray, with its filament, extends 

 to the front of the peritroct, and is contained 1.9 times in the head; 

 the inner ventral rays are not quite half as long as the orbit, and 

 extend but halfway to the origin of the anal fin, the vertical from 

 which passes behind the first dorsal a distance half as long as the 

 fin itself; the height of the first anal ray and of the orbit are equal. 



The trunk is silvery between the anus and the ventral bases and 

 on an area extending thence forward along the sides of the isthmus 

 and upward to the middle of the sides; this silvery region is con- 

 tinued backward as a streak occupying the middle third of the sides 

 of the tail; the abdominal region before the ventral fins has a cop- 

 pery luster; the immediate bases of the paired fins are blackish; a 

 fine black ring surrounds each of the lens-shaped structures on the 

 belly; the rest of the body is brownish, becoming dark below the 

 first dorsal fin. The markings of the head consist of a dark brown 

 region about the occiput; a dark streak along the margins of the 

 postorbital sensory canals, and narrow black streaks along the front 

 margin of the snout, along the inner margins of the lips, and along 

 the sides of the central canal in each mandibular ramus. The sides 

 of the head are bright silvery, but the black lining of the branchial 

 cavity shows through the opercle. The membranes over the sensory 

 canals are transparent, allowing the coloration of the walls of the 

 canals to be visible; the vertical wall of the suborbital cavity is 

 silvery, but its roof is dark; the floor of the interorbital cavity is 

 blackish. The buccal and branchial cavities are lined with silvery 

 everywhere excepting a margin about as wide as the pupil on the 

 outer posterior sides of the branchial cavity; this dark is margined 

 at the extreme edge of the opercular and branchiostegal membranes 

 by a whitish line. The parietal peritoneum is silvery with some 

 diffused brownish color and black spots. 



The "striated" region of the belly consists of a strip, about as 

 wide as the pupil, extending along the sides of the isthmus and 

 backward to above the base of the ventral fin, from which place the 

 striae fade out posteriorly, being traceable about halfway to the 

 anus. The striae are similar to but more extensive than those of 

 tenuis,' they are finer than those of striatissimus, and do not occur, 

 as in that species, on a thickened portion of the skin below the post- 

 clavicle. The end of that bone is much nearer the base of the ven- 

 trals than the anus, the reverse of its position in striatissimus. The 

 gular membrane lacks the median black streak of striatulus, and 

 lacks the double striation characteristic of striatissimus ; it is marked 

 only by numerous black lines somewhat coarser than those on the 

 striated region of the belly. 



