122 GENERA AND SPECIES. 



wards and forwards. The second dorsal and anal are yellowish, the 

 caudal and pectorals blackish. In length this fish reaches 36 inches, 

 but the few British specimens have been smaller. It is a surface- 

 feeder, migrating in shoals, and leaping into the air after its prey. 



Perca. Plate i. PERCIDJE. 



i, fluviatilis, PERCH. Body with vertical bands ; large spinous dorsal. 



The Perch has two dorsal fins, the first with 14 or 15 strong 

 spines, the second with one or two very short spines and 13 or 14 

 rays ; in the anal are 2 spines and 8 or 9 rays, in the caudal 18 rays, 

 in the pectorals 14, in the ventrals a spine and 5 rays. In the 

 lateral line there are from 55 to 60 scales. There are villiform 

 teeth on the jaws, vomer, and palatines, and none on the tongue. The 

 mouth extends to the middle of the eye ; the gill cover has a strong, 

 flat spine, and the edges of the opercles are serrated. The colour 

 is olive green above, with dark vertical bands, and the underparts are 

 yellowish, tinged with pink. The first dorsal is grey, with one or two 

 black spots; the eyes are a rich yellow. The Perch is 5 inches long 

 when two years old, and when old attains a length of 29 inches. 

 Though occasionally found In brackish and even salt water, the 

 Perch is a fresh- water fish, mainly found in ponds and rivers where 

 the current is slow, keeping, as a rule, near the bank, and in deep 

 holes, but in the breeding season betaking itself to shallow parts 

 where the stream runs fairly fast. It feeds on insects, crustaceans, 

 worms, and small fishes, and is best known when under a foot in 

 length. It breeds in its third year, and in the breeding season 

 becomes very bright in colour, with a good deal of red about 

 the fins. 



Peristethus. Plate viii. DACTYLOPTERIDJE. 

 59. cataphraclum, ARMED GURNARD. Snout bifid. 



There are two dorsals ; the first with 7 long spines, the second 

 with a spine and 18 or 19 rays. In the anal there are from 18 to 21 

 rays, in the caudal n, in the pectorals 12, with 2 free appendages, 

 and in the ventrals a spine and 5 rays. The spines of the first dorsal 

 extend some distance above the membrane. The lateral line has 29 

 or 30 scales; the scales are large and bony; there are three angular 

 scales at the base of the caudal, and 3 bony plates between the 

 throat and the anal fin. Along the body are 4 spiny ridges, and 

 the body is octagonal in shape. The snout is long and spiny, and 

 divides into two projections ; there are spines on the gill covers, 

 barbules along the mouth, and one under the chin. In colour this 

 fish is scarlet above and yellow below, the dorsals and anal being 

 crimson. The few that have been caught in British waters have not 

 exceeded a foot in length, but it grows to double that size in the 

 Mediterranean. 



