GENERA AND SPECIES. 89 



191. pikhanlus, PILCHARD. Dorsal nearer head than tail; ventrals 

 below middle of dorsal, and with from 6 to 8 rays. 



193. alosa t ALLIS SHAD. Dorsal nearer head than tail ; ventrals 



below third ray of dorsal and with 9 or 10 rays ; gill- 

 rakers from 60 to 80. 



194. finta, TWAIT SHAD. Dorsal nearer head than tail ; ventrals 



below third ray of dorsal and with 9 rays ; gill-rakers 

 from 20 to 28. 



The Herring has from 17 to 19 rays in the dorsal fin, 16 to 19 in 

 its anal, 18 or 19 in its caudal, 17 in its pectorals, and 9 in its 

 ventrals. In its lateral line there are from 53 to 60 scales ; the 

 scales are moderate in size. The mouth extends to the centre of 

 the eye, which has an adipose lid on each side; the lower jaw is 

 longer than the upper, and is tipped with black. There are no 

 radiating lines on the gill-covers. The abdomen is keeled, but the 

 spines on it are short and weak. In colour the Herring is greenish- 

 blue above, becoming silvery and iridescent on the sides and below. 

 In length it ranges from about 8 inches to 15. It feeds on smaller 

 fish, and minute Crustacea and other marine invertebrates, and 

 swims at any depth, always in shoals, but is captured as a surface 

 swimmer. It squeaks like a mouse when caught. Its migrations 

 do not take it out of the northern seas, though it is found in the 

 Pacific as well as in the Atlantic. When caught young at the mouth 

 of the Thames it is known as whitebait. 



The Sprat has from 16 to 18 rays in its dorsal fin, 17 to 20 in its 

 anal, 19 in its caudal, 16 or 17 in its pectorals, and 7 in its ventrals. 

 In its lateral line there are 47 scales, which are rather larger than 

 those of the herring, and are smooth and deciduous. The mouth 

 extends to the first third of the eye, which has adipose lids. The 

 lower jaw is the longer, and has no black tip. There are no 

 radiating lines on the gill-covers. The abdomen is keeled, and the 

 spines on it are strong and sharp. In colour the Sprat is slaty- 

 blue above, becoming silvery and slightly iridescent on the sides and 

 below. In length it ranges from 4 to 6 inches. Its food is 

 apparently similar to that of the herring, but it is known only as a 

 surface swimmer. It migrates as far south as the Mediterranean. 

 When caught young at the mouth of the Thames it is known as 

 whitebait, as the herring is ; in fact, whitebait consists almost entirely 

 of the young of these two fishes. 



The Pilchard has the dorsal fin at the centre of gravity, so that 

 the body hangs horizontally when held up by the first rays of the 

 fin. The dorsal has 17 or 18 rays, the anal 17 or 18, the caudal 19, 

 the pectorals 16 or 17, and the ventrals 6 or 8. In its lateral line 

 are 29 or 30 scales ; the scales are the largest among the British 

 representatives of the family. The mouth extends to the first third 

 of the eye, the lower jaw being the longer. Like the foregoing 

 species, there are eyelids, but unlike them there are radiating 

 lines on the gill-covers. The abdomen is rounded and the spines 

 weak. In colour the Pilchard is olive green above, and silvery 

 below ; in length it ranges from 8 inches to 14. It has been 

 seen feeding on the bottom, but is caught as a surface swimmer in 

 enormous shoals that crowd together during the day, but spread 



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