238 PROCEEDINGS OF THE ACADEMY OF [1880. 



Opercular region well developed ; the distance from the posterior 

 margin of the eye to that of the operculum being, to the length of 

 the snout, about as eleven to nine. Posterior margin of operculum 

 and sub-operculum forming a continuous bold couA^ex curve. 



Pectorals triangular-ianceolate, fourth and fifth rays longest ; 

 their tips extending to beyond the middle of the pubic bones, 

 ra3'S once or twice bifurcate, the first two excepted. 



Yentrals reaching bej^ond the vent, the third rays longest, the 

 last about two-thirds as long ; all the ra^^s twice bifurcate except 

 the first. 



Dorsal well developed, fourth and fifth rays longest, and con- 

 tained about 1^ times in the greatest depth ; first three rays 

 simple, the others twice bifurcate. 



Anal considerably shorter than the dorsal, but equal in depth 

 to the height of the latter; the first two rays simple, the others 

 (except the last) twice or thrice bifurcate ; first ray about half as 

 long as the second. 



Origin of the dorsal about one-sixth nearer to the tip of the 

 snout than to the centre of the base of the caudal (measuring 

 along the axis of the body), the base of its eighth ray above the 

 anterior axil of the ventrals. 



The tips of the anal rays reach beyond the first caudal 

 accessories. 



Caudal with numerous accessory rays, the longest about half as. 

 long as the outer simple principal ray ; the other principal rays 

 three times bifurcate ; posterior margin of fin triangularly emar- 

 ginate. 



Scales C3'cloid, of variable size ; each scale with 8-16 conspicuous 

 radiating striie on its exposed portion ; ihe striae and their inter- 

 spaces crossed by numerous, much less distinct concentric striae. 

 Engaged portion of each scale with numerous diverging striae, less 

 distinct than those of the free portion. Scales along and near the 

 lateral line larger than those above and below, and increasing 

 considerably in size posteriorly, as do also those above and below, 

 so that the largest scales of the body are upon the peduncle of the 

 tail. The scales diminish much more rapidl}- in size downwards 

 than upwards, so that those of the abdominal region and behind 

 the pectoral base are by far the smallest. Scales somewhat 

 pentagonal, the length exceeding the height ; those upon the 

 caudal peduncle almost twice as long as high. 



