ACERINA CERNUA. 35 



The ctenoid scales are moderately large ; fifty-five to sixty are found 

 in the lateral line, with six to seven rows above, and ten to twelve rows 

 below the lateral line. A part of the breast in front of the ventral fin is 

 naked. The scales resemble those of the Perch and the Apron, but they are 

 more oval, and the spines are sharp and conical, longer than those of the 

 Apron, and more numerous than in the Perch. The lateral line is nearly 

 straight, and follows the outline of the back ; it is very conspicuous, on account 

 of the large size of the mucus-canals, which open through the scales. 



The internal organs have much in common with those of the Apron and 

 the Perch. The eggs are of large size and yellowish in colour ; the ovaries 

 form closed sacs; the uro-genital opening is a perforation in a thick short 

 papilla behind the anal aperture. The stomach has three pyloric appendages, 

 and the intestine has three folds. The vertebrae usually number thirty- 

 five or thirty-six, according to Fatio, though Valenciennes records thirty-seven, 

 of which fifteen are abdominal and twenty to twenty-two caudal. 



The colour is greenish-olive, mottled and spotted with brown. The sides 

 are brassy yellow, the belly an opalescent white, with the breast and throat 

 pale red. Upon the spinous part of the dorsal fin the brownish-black spots 

 generally form four or five rows between the spines. On the caudal fin the 

 spots often cover the rays. The pectoral fin is sometimes free from spots or 

 irregularly marked. The anal and ventral fins are white, with red tinting. 

 The iris is black, with a golden-yellow colour below. • 



In England this little fish is rarely more than three or four inches long, 

 but sometimes reaches a length of six or seven inches. An example from the 

 Elbe is said to have measured nine inches, and Bloch mentions one from a 

 Prussian lake which was a foot long. In Siberia it is taken seventeen to 

 eighteen inches long, and weighing a pound and a half. 



This is essentially a northern species, being common in the rivers of Russia, 

 Northern and Central Scandinavia, and Siberia, and spread through England, 

 France, Switzerland, and Central Europe. According to Cuvier, it is espe- 

 cially common at the confluence of rivers. It has not been recorded from 

 Spain, Italy, or Greece. In Scandinavia it is known, from its slimy covering, 

 as Snorgers, snor being nasal mucus, and r/ers the popular name of the fish. 



This fish, the Kaiilharsch of the Germans and Gremille of the French, is 

 found indifferently in rapid streams and sluggish waters, where it frequents 

 sandy bottoms, and takes to deep water in the winter. It does not thrive on a 

 clay bottom, perhaps because it lives at the bottom of the water. It passes 

 most of the year in solitude, is sluggish, moves by short shoots, and waits for 

 its prey ; but when alarmed it is active enoug-h to have originated the Swedish 

 saying, " agile as a Ruff." 



