264 SALT-WATER FISHES 



In about six days or rather less, the temperature varying 

 between 62° by day to 51 "3° at night. At St. Andrews, 

 however, in May, these eggs took as long as ten days 

 to hatch. 



The larva, on emerging from the egg, measured less than 

 Yo in., and was not so developed as that of the lesser weever, 

 of which Mr. Brook also made a study. It has three conspicu- 

 ous spots of black, and at a rather later stage the lower jaw 

 projects, the eye is a pronounced blue, there is a greater 

 proportion of black colouring matter, and the pelvic fins are 

 tipped with black and very long. The barbels first appear 

 when the little fish is about -| in., and are all distinctly 

 developed at i in., but there is apparently some variation 

 in the degree of development at any given age. One measur- 

 ing rather over i in. was found to have lost much of the 

 silvery pigment and to have taken up its residence in the sand. 

 By their first January — i.e. at about six months old— the rock- 

 lings of this species are about 2 in. long, and Cunningham 

 found that rocklings measuring i in. their first May had 

 grown to 5 in. by the May following. 



The Four-bearded Rockling [M. cimbria) is the smallest 

 and least common of our British kinds, the largest recorded 

 example being 14 in. long. It differs from the last kind 

 chiefly in the number and distribution of its barbels, having 

 one on the chin, one on the upper lip, and two on the snout. 

 As in all rocklings, the front dorsal fin lies in a groove, one 

 long ray only showing above the line of the back. It has 

 recently been recorded by Holt from the Bristol Channel, but 

 it is nowhere very common on our coasts. Mcintosh and 

 Masterman describe it as not uncommon in the Firth of Forth, 

 but only about ten were recorded in that locality between 1890 

 and 1900,* which does not suggest great abundance. One was 

 picked up near North Berwick in the October gales of 1898, 



• See Eagle Clarke, " Fishes of the Firth of Forth," in Ann. Scot. Nat. 

 Hist, October, 1900, p. 210. 



