NATURAL SCIENCES OE PHILADELPHIA. 26* 



hind the preoperculum exceeds a half of its length, or a ninth (11-100) of the 

 total ; that behind the eyes equals eight-elevenths of the greatest or 8-100 of 

 the total length. 



The eyes are similar to those of Dactyloscopies tridigitatus. The diameter of 

 the orbit is contained nearly seven times (3-20) in the head's length, and 

 equals 3-100 of the total. The distance between the eyes equals two-thirds of 

 a diameter, and that from the snout a whole diameter. 



The preoperculum has the same form and proportions as Dactyloscopiis tri- 

 digitatus. The pores are very indistinct or obsolete. 



The opercular fringe is formed by about eighteen filaments, the lowest of 

 which are scarcely extended beyond the margin. 



The commencement of the dorsal fin is distant from the snout a sixth 

 (16-100) of the entire length. It has about forty-two rays, of which the first 

 eleven appear to be simple and inarticulated, and the rest are divided as the 

 typical species. 



The anal fin commences nearly under the sixth ray of the dorsal fin ; it has 

 about thirty-four rays, the first two of which are simple and inarticulated. 

 The rest are branched. 



The caudal fin has ten articulated rays, of which eight are branched and 

 two simple ones, one above and another below. 



The scales are of moderate size and regularly imbricated. Each one is short 

 or little oblong, with the nucleus little eccentric and with well defined con- 

 centric striae on the whole surface ; there are no radiating grooves or ridges. 

 The lateral line runs above through thirteen scales, is then deflected and con- 

 tinued very obliquely on three, and again runs through the fifth row from the 

 back along about thirty-two scales to the caudal fin. 



Total length, (2-6,) 100 



Greatest height 16 



Height behind last dorsal ray 4 



Thickness at pectorals 11 



Head Length 20 



Height at preoperculum 11 



Thickness at preoperculum 11 



" behind eyes 8 



Height at eyes 9 



Interorbital area 2 



Eyes Diameter 3 



Distance from snout 3 



Dorsal Distance from snout 16 



Caudal Length, (assumed) 12 



This species is closely related to the Dactyloscopiis tridigitatus, but is readily 

 known by its color and the number of scales through which the anterior part 

 of the lateral line runs, as well as by its stouter and more robust body, its 

 longer and wider head and the less distance between the snout and the com- 

 mencement of the dorsal fin. The caudal fin is mostly destroyed, and the 

 above table of measurements has been calculated for the total length, on the 

 supposition that the caudal fin, as in the type of the genus, bears the propor- 

 tion to the entire length of twelve to a hundred. The pectoral and ventral fins 

 have been also mutilated. 



A single specimen of this species was obtained by my learned friend, the 

 Professor of Zoology and Comparative Anatomy in the Royal University of 

 Havana. In testimony of my appreciation of his labors to elucidate the natu- 

 ral history of Cuba, I have dedicated the species to him. The specimen has 

 been presented to the Smithsonian Institution. 



Dacttloscopus pectoralis Gill. 

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

 1861.] 



