148 ON SCOMBER PTJNCTATTTS AND S. SCOMBER. 



the eyes, along the back and sides to the tail, the surface was 

 thickly covered with (black) spots of the size of a small pea, gene- 

 rally round and well defined, but a little larger, and elongated 

 transversely on the summit of the back. The spots ended a little 

 below the lateral line, and the belly was pure white ; the surface 

 between the carinations of the tail a bronzed yellow colour." 

 Certainly if the description of the colours had been taken from 

 the specimen I am recording, it could hardly have been more 

 accurate ; while, as it is, by such, or markings alone, that the distinc- 

 tion can be shown between the " Dotted " and the " Common " 

 Mackerel, it must be conceded that the example here figured 

 (PL VII.) represents the former variety. 



D. 13 [ ^ + y. P. 21. V. 1/5. A. 1 | ^ + v. C. 17. 



Extreme length 14, to base of caudal fin 12 - 75, of each caudal 

 lobe 2"25, of head 3 - 2 inches. Dorsal fin, length of base 2 inches, of 

 second spine 1'3, of interspace between two dorsal fins 23, of base 

 of second dorsal TO, of base of anal fin ri, length of pectoral fin 1*5.. 

 Lower jaw very slightly the longer. Eyes, diameter one fourth 

 of the length of the head, 1| diameter from the end of the snout 

 and 1 apart. The posterior extremity of the maxilla reaches to 

 beneath the middle of the eye. Air-bladder absent. Length of 

 intestines from pylorus to vent 105 inches. The example was a 

 female, and the ova not quite mature. The number of its fin-rays, 

 and even scales, as well as its proportions, agree so well with 

 some British examples of J3. scomber, that further description 

 appears to be unnecessary, except to remark that the interorbital 

 space is slightly broader in this specimen than some of the 

 Common Mackerel ; but I find such liable to individual varia- 

 tions. 



The European forms of Mackerel may be subdivided, for the 

 sake of convenience, into (1) those possessing an air-bladder and 

 (2) those in which this organ is deficient. They are as follows: — 

 Scomber pneumatopTiorus, which extends from the Mediterranean 

 southwards, and 8. colias, also aMediterranean form, but visiting the 

 British isles, have both an air-bladder ; consequently the " Dotted 

 Mackerel" cannotbea variety of eitherof those species. S. scomber, 

 however, has no air-bladder, and is (excepting in colour) identical 

 with the form under review,whileityet remains to ascertain whether 

 the "Scribbled Mackerel," also destitute of an air-bladder, is not 

 merely another variation in colour of the same species. Respect- 



