7. sci^NA. 287 



process, bent forwards and upwards, near its base. The jju^'c bones 

 have two ridges at the lower side and no posterior process. 



It will be evident, from the description given, that the arrange- 

 ment of the system of the muciferous channels is the same as in 

 several Percidce {Acerina cerniui, Percarina demidoffii, &c.), or, in fact, 

 as it is present, in a rudimentary state, in aU the Acanthopterygii, and 

 that it does not afford, of itself, a character by which the Scicenidce 

 may be distinguished from other fishes. 



There are twelve abdominal and thii'teen caudal vertebra, the 

 length of the former portion of the column being to that of the cau-* 

 dal as 12: 17. The third and foiu'th vertebrae are famished infe- 

 riorly with a pair of ridges, to which the air-bladder is fixed ; each 

 abdominal vertebra has a pair of ribs. The neural sjiines of the first 

 six vertebrae are broad, compressed, and strong ; the corresponding 

 interneurals, or those of the spinous dorsal, are very broad, some- 

 times confluent, but exceedingly thin. The first interhaemal is long, 

 slender, equal to the length of the first eight vertebrae, and attached 

 to the thirteenth vertebra. 



There is an outer series of larger teeth in the upper jaw, and 

 within it a very narrow band of vilhform teeth ; in the lower jaw the 

 stronger teeth are mixed Avith those of the narrow \dlliform band ; 

 and several on the sides are rather stronger than those in front of 

 the upper jaw. The teeth of the upper pharyngeal bones are arranged 

 in several roundish patches, and are card-like for the greater part. 

 The inferior teeth form a narrow, long, A-iUiform band. 



2. Sciaena crouvina. 



Johnius crouvina, Castelnau, Anim. nouv. ou rares de VAiner. du Slid, 

 Poiss. p. 11. pi. 5. f. 1. 



D. 9 ^. A. -|- (in the figure ; y in the description). 



The height of the body is four times in the total length, the length 

 of the head 3|. The snout is not obtuse, with the jaws equal (see 

 figure quoted). The dorsal fins are united by a membrane, one-third 

 as high as the soft dorsal ; caudahs rounded ; the second anal spine 

 very short, equal to, or even shorter than, the width of the orbit (see 

 fig.). Axil with a deep black blotch. (Cast.) 



Rio Crixas, Ai-aguay. 



3. Scisena aurata. 



Johnius auratua, Castelnau, Anim. nouv. ou rares de TAmer. du Sad, 

 Poiss. p. 12. pi. 4. f. 2. 



The height of the body is equal to the length of the head, and 4| 

 in the total. The snout is convex, -ndth the iipper jaw slightly 

 overlapping the lower ; operculum with one distinct point only. 

 Caudalis pointed ; the anal spine thick, its length being 2g in that 

 of the head. Coloration uniform. (Cast.) 



Ucayala. 



