434 DR. GUNTHER ON THE FISHES OF CENTRAL AMERICA. 
85. TRacHyNoTus FasciAtus. (Plate LXIX. fig. 4.) 
Trachynotus fasciatus, Gill, Proc. Ac. Nat. Se. Philad. 1863, p. 86. 
glaucoides, Giinth, Proc. Zool. Soc. 1864, p. 150. 
D. 6| 5. A. 2\z5 
Closely allied to 7. glaucus, but with the body more elevated. ‘The height of the 
body is one-half of the total length (without caudal); the length of the head two- 
sevenths. The maxillary extends to below the middle of the eye. Anterior dorsal and 
anterior anal rays, and the caudal lobes, much prolonged, the length of the latter being 
two-sevenths of the total. The ventral fin does not eatend to the vent. Five narrow 
blackish vertical bars across the lateral line. 
One specimen, 7 inches long, was obtained by Mr. Salvin at San José; two others, 
11 inches long, were obtained by Capt. Dow at Panama. 
Description.—This species has the body (without caudal) of a rhomboidal form, its 
greatest height being between the last spine of the dorsal and the vent, and one-half of 
the total length (without caudal); the upper profile between the dorsal and the snout is 
oblique, feebly convex over the eye. The length of the head is contained thrice and one- 
half in the total (without caudal). ‘The diameter of the eye is rather more than the length 
of the snout, and contained thrice and two-thirds in that of the head. The cleft of the 
mouth is narrow; the maxillary reaches nearly to the level of the centre of the diameter 
of the eye; its length is a little more than one-third of that of the head. The width of 
the space between the eyes is more than one-third of the length of the head, or equal to 
the distance from the tip of the snout to the centre of the eye. Praoperculum with 
the hinder margin straight, and at a right angle with the lower border, which is also 
straight and parallel with the axis of the body. Operculum small, narrow, about two- 
thirds as long as high; the hinder border of the opercular apparatus is formed almost 
entirely of the sub- and interoperculum ; it is rounded and membranaceous: the line of 
the separation between the operculum and suboperculum is at right angles with that 
between the sub- and interoperculum. There is a recumbent spine before the com- 
mencement of the first dorsal, and in a line with the posterior part of the axil of the 
pectoral ; the dorsal spines, seven in number, are short; the first is minute, but erect, 
and not attached by any apparent membrane to the second; the others show a slight 
progression in dimensions, and are united by a low membrane. The base of the soft 
dorsal is not twice as long as that of the spinous; the first two rays, which are the 
longest, project considerably beyond any of the others, and are equal to half the length 
of the body (without the caudal); the following rays diminish very rapidly in length, 
and from the eighth ray to the last the fin is scarcely higher than the spinous dorsal, 
and its upper edge almost straight. The distance between the dorsal fin and the 
caudal is equal to that between the anal and caudal. ‘The anal fin is preceded by three 
short spines about equal to the fourth, fifth, and sixth of the dorsal. The base of the 
