178 SCOMBERID.E. 



of the head, part silvery, part dusky ; operculum rounded ; 

 the last ray of the first dorsal fin connected by a membrane 

 to the first ray of the second dorsal fin ; the two spines 

 anterior to the anal fin slightly united by a membrane to 

 each other, and to the base of the first ray of the anal fin. 

 The ventral fins are placed in depressions ; the two spines 

 and the anterior part of the anal fin are lodged in a groove. 

 The curve of the lateral line is over the vent ; the body from 

 thence to the tail becomes quadrangular, on account of the 

 bony plates of the lateral line, which are terminated by a 

 spine pointing backwards, and forming a strong carina on each 

 side quite to the tail. 



The number of fin-rays is as follows : 



D. 8, 1 + 32 : P. 21 : V. 1 + 5 : A. II. 1 +26 : C. 17. 



" The colour is a dusky olive above, changing to a resplen- 

 dent green, with a bluish waved gloss ; sides of the head, 

 and beneath the lateral line, silvery, with waved reflections ; 

 dorsal fins dusky, the lower fins quite pale ; on the margin of 

 the gill-cover, above the pectoral fin, a large black spot : the 

 throat and under part of the jaw is also black. This speci- 

 men was caught on a whiting-hook baited with sandlaunce." 



The Scad, or Horse-Mackerel, occurs in the Mediterra- 

 nean and at Madeira: some variation, however, is found in 

 the number of lateral plates. 



In a specimen of the Scad of our seas, the number of these 

 lateral plates was seventy- four. 



