Ichthyology of the. Firth of Forth. 51 



of about a foot and a half square, between two and three hundred fish,, 

 the greater part of which were white-bait of small size, not more 

 than two inches in length ; the remainder were sprats, young herring, 

 and fry of other fish. 



In their habits they appear to be similar to the young of the her- 

 ring, always keeping in shoals, and occasionally swimming near the 

 surface of the water, when they often fall a prey to aquatic birds. 



I have no doubt that the white-bait will be found to exist in 

 the Firth of Forth throughout the whole of the year in considerable 

 quantity, and that the fishermen would find it a new source of income, 

 equal or superior to the spirling fishery, did they use the mode of fish- 

 ing for white-bait that is practised in the Thames. But in conse- 

 quence of the large extent of the estuary, and of no means being 

 used exclusively for the capture of these fish, we can form but a faint 

 idea of the number that may there exist. 



The white-bait net which is used in the Thames is not large; the 

 mouth of it measures only about three feet across, but the mesh of 

 the hose, or bag-end of the net, is very small. A boat is moored in 

 the tide-way, where the water is from twenty to thirty feet deep ; 

 and the net with its wooden frame is fixed to the side of the boat. 

 The tail of the hose, swimming loose, is from time to time brought 

 into the boat, the end untied, and its contents shaken out. The 

 wooden frame forming the mouth of the net does not dip more than 

 four feet below the surface of the water. 



The largest specimen of Clupea alba that I have met with, taken 

 from the Firth of Forth, measures five inches in length. The up- 

 per part of the back, from the nape to the tail, is of a pale green- 

 ish ash-colour, the sides, gill covers, pectoral, ventral, and anal 

 fins, of a beautiful pure white ; the dorsal and caudal fins straw 

 colour, minutely spotted with dark brown. The head on the sum- 

 mit in voung specimens is marked with a large brown spot, which 

 is divided anteriorly by a white line. Each orbit on the superior 

 margin is tinged with black, as well as the posterior inferior mar- 

 gin, but in a less degree. The shape of the body resembles that of 

 the young herring, but it is more compressed and of a deeper form. 



The first ray of the dorsal fin commences exactly midway between 

 the point of the upper jaw and the end of the middle caudal ray ; 

 the ventral fins are placed behind the third ray of the dorsal ; the 

 tail is deeply forked, the middle ray being not quite half the length 

 of the longest ray of the same fin. The fin rays in number are, 



D. 17; P. 15; V. 9 ; A 15 ; C. 20 ; Vert. 56; Coecal append, about 15. 



The head, in a specimen five inches long, is not quite one-fourth 



