PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 25 



contained 3J times in length of body. The width of the interorbital 

 region (0.075) is as much less than the length of snout (0.08) as it is 

 greater than the length of the operculum (0.07). The length of the 

 maxillary (0.11) is nearly equal to that of the ventral (0.115), and more 

 than double the diameter of the orbit (0.05). The length of the man- 

 dible (0.14) is double that of the operculum. 



The distance of the first dorsal fin from the snout (0.34) is slightly 

 greater than that of the pectoral (0.325), and less than that of the ven- 

 tral (0.38) by a distance nearly equal to the diameter of the orbit ; it is 

 also a trifle less than half the distance from the snout to the origin of 

 the anal (0.70). 



The length of the first dorsal spine (0.145) is double the length of the 

 longest anal ray (0.0725). The distance from the origin of the first 

 dorsal to the end of the base of the second dorsal (0.36) is four times 

 the length of the anal base (0.09). 



The length of the pectoral (0.15) is less than half its distance from 

 the snout (0.325), and exactly half the length of the head ; it is con- 

 tained 6| times in the length of the body ; its origin is slightly in 

 advance of the origin of the dorsal, while its extremity reaches to the 

 vertical from the tenth dorsal ray. 



The length of the ventral (0.115) is about one-third that of the dis- 

 tance of the first dorsal from the snout. 



The corslet is very prominent. Its contour is defined by lines begin- 

 ning at the edge of the branchial cleft, about midway between the axil 

 of the pectoral and the median line of the belly, extending below, beyond, 

 and around the extremity of the pectoral (which, when normally placed, 

 touches with its tip the outer margin of the corslet), then extending be- 

 yond its tip for a distance nearly equal to its length, round up into the 

 lateral line, down which a narrow tract of scales continues to its extrem- 

 ity, though narrowed to a single row after passing its curve ; passing 

 the lateral line, the contour of the corslet curves forward and inward, 

 then ascending to a point distant from the median line of the back about 

 the diameter of the orbit, it follows backward in a direction parallel to 

 this line, to a point opposite the posterior extremity of the second dorsal, 

 where it curves upward to the median line of the body, and completes 

 its circuit. 



When viewed from above, the rows of scales appear to be arranged 

 concentrically about the origin of the first dorsal fin. The scales are 

 largest along the edges of the pectoral arch and the dorsal fin, decreas- 

 ing rapidly in size as they recede from these regions. There are about 

 thirty rows between the dorsal and the upper margin of the pectoral, 

 normally placed. 



Radial Formula.— D. XIV, 2 + 12, VIII. A. 2 + 12, VII. P. 28. V.6. 



Color. — The upper parts must have been deep blue in life ; the belly 

 and flanks below lateral line, the opercles, and throat, pearly opalescent 

 white. The lower part of the pectoral arch and tracts at the base of 



