THE ARMED BULL-HEAD FAMILY. 143 



above (4^ to 6^ inch) would be from 10 months to 13 months 

 old, whilst the series of 2f to 3 inches occurring in June may 

 be from 9 to 10 months and the second series in the same 

 month (4f to 6 J in.) would probably contain individuals from 

 two broods, the smaller being about 14 months and the larger 

 26 months. There is still uncertainty, however, on these 

 points. 



The curve of growth from specimens measured by Mr 

 Williamson, of this Laboratory, gives an average length of 

 4 inches at the age of one year and of 6| inches at two 

 years, which is increased to 9 inches or more at the end of 

 the third year. It is probable that the gurnard, like most 

 food-fishes, comes to maturity during its third year or a little 

 later. The number of females appears to be in excess of the 

 number of males in the proportion of 4 to 1 and the male is, 

 on an average, slightly smaller than the female. 



The Armed Bull-Head Family. Cataphracti. 



The Armed Bull-head. (Agonus cataphractus, L.) 



No form is more familiar in sandy bays in the naturalist's, 

 or small-meshed, trawl than this species, yet its spawning was 

 more or less unknown until recently. Couch gives nothing 

 more than that the spawning-period is stated to be spring ; 

 while Day describes a female, 5 inches long, fi-om Southend, in 

 February, as having its comparatively large eggs nearly ripe. 

 In the Researches^ it was mentioned that the females caught 

 in the sprat-nets in the Tay showed nearly ripe ovarian eggs 

 on the 16th December, and that they had a dull golden or 

 dull yellow colour, their diameter being '07 in. and that of 

 the oil-globule 0216 in. The capsule is minutely dotted with 

 punctures arranged in linear series, and the surface has well- 

 marked reticulations (Plate I, fig. 8). It is added that the 

 species seems to spawn from January (or perhaps December) 

 to April, females with nearly ripe ova occurring in March. 



1 Mcintosh and Prince, loc. cit, p. 674. 



