58 



ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



Family— MJENID^. 

 1. Gerres Gula. Cuv.et Vol.? 



Gerres Gula, Cuv. et Vol. Hist, des Poiss. torn. vi. p. 349. 



Form.— Greatest depth one-fourth of the entire length. Back but little elevated. Space between 

 the eyes flat, with a fovea in the middle, which is prolonged in a channel nearly to the extremity 

 of the snout. Length of the head exceeding its depth by one-fourth, and contained about three 

 times and three quarters in the entire length. So much of the maxillary as is visible is of an 

 oval form, its length being twice its breadth at its posterior extremity. Suborbital with the 

 lower margin very indistinctly notched, and not denticulated. Eyes very large, their diameter 

 contained twice and three quarters in the length of the head. The two orifices of the nostrils 

 of nearly equal size. No denticulations on any of the pieces of the gill-cover. A narrow band 

 of very minute velutine teeth in each jaw, those above hardly visible to the eye, but sensible to 

 the touch : none on the vomer, palatines, or tongue. 



Dorsal with the first spine extremely short ; the second has a small piece broken off at the 

 tip, but appears to have been about the same length as the third, which last equals two-thirds 

 of the depth of the body; the fourth and fifth are a little shorter than the third; the succeeding 

 ones gradually decreasing, as in the other species of this genus: all the spines are moderately 

 slender, the anterior ones slightly arcuate, with scarcely any appreciable difference in the degree 

 of stoutness in the first four. Anal with the first spine extremely short ; the second obviously 

 stouter than any of the dorsal spines, but much shorter, being only half the length of the second 

 dorsal spine, or one-third the depth of the body ; the third spine is a trifle longer than the 

 second, but much slenderer. Caudal deeply forked ; the lobes worn at the tips in this specimen, 

 but their length, when perfect, probably about one-fourth, or somewhat less, of the entire length 

 of the fish. Pectorals narrow and pointed, a little shorter than the head, and contained four 

 and a half times in the entire length ; fifth ray longest. Ventrals a little behind the pectorals, 

 and not more than two-thirds their length, or scarcely so much ; the spine a little shorter than 

 the soft rays, and of about the same degree of stoutness as the dorsal spines. Elongated scale 

 in the axillae of the ventrals about three-fourths the length of the spine, of a narrow lanceolate 

 form, ending in a very fine point. 



D. 9/10; A. 3/7; C. 17, &c. ; P. 14; V. 1/5. 



Length 3 inc. (i lines. 



Colour.— Not noticed in the recent state. In spirits, it appears of a uniform silvery, with the back 

 and upper part of the sides inclining to dusky olive: no bands or any particular markings: 

 fins pale. 



Habitat, Rio de Janeiro. 



