REPORT ON ICHTHYOLOGY. 409 



to the nostril, and posteriorly nearly straight. The abdominal outline trom the ven- 

 tral fins to the snout is scarcely curved, and behind those fins is almost straight. 

 The greatest height of the body immediately anterior to the dorsal tin equals a fifth 

 of the total length from the snout to the cmarfji nated border of the caudal fin, and is 

 twice as great as the width at the same place. 



The caudal peduncle is of moderate size, the distance between the posterior angle 

 of the anal fin and the insertion of the caudal equaling fifteen hundredths ot the total 

 length, the height behind the anal, thirteen hundredths, and that at the base of the 

 caudal eight hundredths. 



The head is conical in . profile, flattened and depressed above. The projecting, 

 but flattened, muzzle is vertically rounded. The length of the head from the snout 

 to the margin of the operculum forms a fifth of the total ; the upper surface to the 

 scaly nape equals three-fourths of the latter. The width behind equals a ninth of the 

 total length, and at the pupil an eleventh. 



The eyes are of moderate size, subcircular, entire, lateral, but near the plane of 

 the superior surface of the head; they are situated entirely m the anterior half of the 

 head, the distance of the pupil from the snout equaling two-fifths of the head's length 

 and the diameter of the eye itself a fifth of the same. The interorbital space is equal 

 to an eleventh of the total length. 



The dorsal fin commences between the fourth and fifth tenths of the total length 

 from the snout, and is higher than long. The base equals a tenth of the total length ; 

 the longest ray fourteen hundredths, and the last eight hundredths. 



The anal fin commences between the sixth and seventh tenths of the length trom 

 the head. Its size is less than that of the dorsal, the base equaling eight hundredths of 

 the total length, the longest ray thirteen hundredths, and the last one seven hun- 

 dredths. 



The caudal fin is forked, and its lobes are equal. The central rays constitute an 

 eighth of the total length, while the longest rays exceed a fifth of the same twenty- 

 one hundredths. . 

 The pectoral fins are emarginated or subfalciform ; the longest rays equal a fifth 

 of the length, and are four times longer than the shortest. 



The ventral fins are inserted beneath the first rays of the dorsal; the external 

 angles of their bases are distant from each other between six and seven hundredths of 

 the total length. Each fin has a convex margin, and its longest ray equals an eighth 

 of the whole length. 



The radial formula is as follows : 



D. 3. 6. h A. 3. 6. h C 4. I. 7. 8. I. 5 ; P. 1. 15; V. 2. 7. 

 The first simple rays of all the fins, except the pectoral, are rudimentary. 

 The scales are of quite large size, there being about fifty perforated for the lat- 

 eral line; under the dorsal fin, there are six rows above and seven below the lateral 

 line Each scale is oblong, or sometimes nearly as high as long, vertical at its base, 

 and rounded behind ; there are generally about ten diverging stria. 



52 B IT 



