268 PROCEEDINGS OF THE ACADEMY OF 



head forms more than a fifth (21-100) of the same ; its greatest height above 

 the preoperculum equals 12-21, and that at the articulation of the lower jaw 

 10-21 of its length. Its greatest width equals two-thirds (14-21), and that 

 behind the eyes more than one-third (8-21) of its length. The dorsal fin 

 commences at the eighteen-hundredths of the length. The caudal fin forms 

 14-100 of the total length ; the pectoral 22-100. The anterior part of the 

 lateral line runs through thirteen scales, is deflected on three, and then con- 

 tinued along the fifth row from the back through twenty-four. 



D. 12, 22. A. 2, 26. C. 1, 1, 4, 4, 1, 1. P. 12. V. 3. 



The color is a light brownish yellow, with dark spots on the back, arranged 

 in lines forming the outlines of about six quadrangular areas, from the angles 

 of which irregular lines proceed downwards and' converge towards those de- 

 parting from the angles of the adjoining areas. Such is the pattern of colora- 

 tion, but it is subject to considerable irregularity. More scattered and irregu- 

 lar spots or dots are often present beneath the lateral line. The head is rather 

 lighter and sometimes suffused with pink above. A transverse band or blotch 

 divided in front is present between the orbits behind. Four rays also diverge 

 in pairs from each orbit ; one from the front ; a bifurcated one from the an- 

 teroinferior angle ; and two from the posterior border. On the crown are two 

 dark spots. There is a transverse sinuated nuchal line. Behind and below 

 the orbit is a whitish area, with a dark spot before and behind. The upper 

 angle of the operculum is whitish, bounded in front by a dark line or spot. 



The height behind the nape is less than a seventh of the total length (15-100) . 

 That at the caudal peduncle behind the last dorsal ray equals a third of the 

 greatest, (5-100 of the length). The thickness at the bases of the pectorals 

 equals 12-100 of the length. 



The head is not so plane as iu the Caribbean species, and the sides less 

 angulated. The length from the tip of the lower jaw to the end of the bony 

 operculum constitutes more than a fifth (21-100) of the total. Its height 

 between the crown and the inferior margin of the preoperculum exceeds 

 twelve-hundredths (12-100) of the total length. The height at the articula- 

 tion of the lower jaw equals a tenth (10-100) of the same. The width of the 

 head behind the preoperculum equals a seventh (14-100) of the total length, 

 while the width behind the eyes, is eight-fourteenths of the greatest, or 8-100 

 of the length. 



The eyes are small, the diameter equalling a tenth (7-21) of the head's 

 length ; they are separated from each other by a space equalling a diameter, 

 and their distance from the upper jaw or snout is equal to a seventh (3-21) of 

 the head's length. 



The preoperculum has nearly the same form as that of Dactyloscopies tridi- 

 gitatus, but it is rather broader at the angle ; the pores are well developed. 



The opercular fringe is formed by ahout eleven or twelve free filaments. 



The dorsal fin commences at 18-100 of the length from the snout, and has 

 about thirty-four rays, the first twelve of which are apparently simple and 

 inarticulated. 



The anal fin commences nearly under the sixth or seventh dorsal ray, and 

 has about twenty-eight rays, the first two of which are simple. 



The caudal fin forms a seventh (14-100) of the total length. It has eight 

 branched rays, two simply articulated ones, and two simple, one above and 

 one below. 



The pectoral fins have twelve rays, the fifth of which is longest, but the 

 fourth and sixth are also much longer than the adjoining ones. The longest 

 exceeds in length a fifth (22-100) of the entire length. 



The ventral fins are similar in structure to those of its allies. The internal 

 ray is as long or longer than the median, and equals an eighth (12-100) of 

 the total length. 



[Sept. 



