ORE A T BRITAIN. 99 



prcopercle, and the armature of the scales on the lateral- 

 line, the scales on the body, and the adipose eyelids. But 

 the single British species is well characterised by its entire 

 lateral-line being armed with large keeled plates. 



Geographical distribution. The fishes composing the 

 genus Caranx, or " Horse-mackerels," are spread from 

 Norway and Sweden throughout most of the temperate 

 and tropical seas, more especially abounding in the latter, 

 where they attain to a large size, and are not considered 

 unsuitable for the table, though some have been reported 

 as poisonous at certain times in particular localities in the 

 tropics, probably due to the food on which they have been 

 living. 



Scad (Caranx trachurus). 



. Names. Scad, which term is said to denote the inferior 

 I quality of its flesh ; rock herring (Aberdeen) ; buck-mackerel 

 \ (Banff). 



B. vii, D. 8 | ^ V. -L, A. 2 | ^ L.l. 73, CJEC. pyl. xii., 

 Vert, -j^ 



Length of head 4 to 4^ ; height of body 5 to 5^ in the 

 total length. Eye. Situated above the middle of the 

 height of the head ; it has a wide posterior adipose lid 

 extending nearly or quite to the edge of the pupil, and also 

 a much narrower anterior adipose lid. Diameter of eye 

 from 3^ to 3f in the length of the head, from I in the 

 young to li diameters in the adult from the end of the 

 snout, and nearly I diameter apart. The lower jaw the 

 longer ; the maxilla reaches to beneath the first third of 

 the eye. Free portion of tail wider than deep. Teeth. 

 Minute in the jaws, also on the vomer, palatines, and in 

 a band along the middle of the tongue. Fins. Dorsal 

 spines weak, increasing in length to the fourth and fifth. 



H 2 



