54 Ichthyology of the Firth of Forth. 



slender, and few in number ; they are situated on the most ante- 

 rior parts, and are more obvious on the lower than on the upper 

 jaw ; the tongue as well as the roof of the mouth is also armed with 

 fine teeth, their points being slightly bent inwards. The under jaw 

 is the longest. The belly is strongly serrated as far as the anal 

 aperture. The convexity of the dorsal and abdominal lines is much 

 greater than is observed either in the white-bait or the herring. 

 The fin rays in number are. 



D. 17 ; C. 19 ; P. 15 ; V. 7 ; A. 18 ; Vert. 48 ; Ccecal append, about 12. 



The dorsal fin commences exactly half way between the point of 

 the lower jaw and the end of the middle caudal rays. * 



The ventral fins arise anterior to a vertical line dropped from the 

 origin of the first dorsal ray, and have distinct axillary scales, nearly 

 half as long as the fin, which are always present in a recent and per- 

 fect sprat, t 



The scales are large, about the size of the orbit, round, and very 

 deciduous. They are placed in seven rows between the dorsal and 

 ventral fins. 



The sprat differs from the herring, white-bait, pilchard, and shad 

 in two most striking characters ; in having only 48 vertebrae, and 

 in having the origin of the ventral fins placed before a vertical line 

 dropped from the commencement of the first dorsal ray. 



Clupea harengus. — (The Herring.) Tab. I. Fig. 3. Dorsal fin half 

 way between the point of the upper jaw and end of the long caudal rays. 



Herrings enter the Firth of Forth about the end of December, 

 or the beginning of January, and remain two or three weeks at the 

 mouth of the estuary before they attempt to ascend. This delay 

 seems greatly to depend on the state of the weather, for in some 

 seasons when it is mild and fine, the herring has been observed to 

 swarm in the Firth off Musselburgh in the early part of January ; 

 whilst in the rough and stormy seasons they do not make their ap- 

 pearance in that part of the river before the middle of February, 

 and always disappear before the end of March. They seem to visit 

 the Firth regularly every winter, and a season very seldom passes 

 without a few being captured and sent to the Edinburgh market. 

 Some years they appear in much larger shoals than in others, the 

 reason of which is not accounted for. In the year 1816, pilchards 



* In YarreH's British Ichthyology, vol. ii. p. 124, the dorsal fin is said to 

 commence exactly half way between the point of the lower jaw and end of the 

 caudal rays. 



f In Yarrell's British Ichthyology, vol. ii. p. 124, it is there stated that the ven- 

 tral fins arise in a vertical line under the first dorsal ray, and have no axillary scales. 



