134 SCOMBRID.E. 



short elevated lacerato-serrate crests or ridges of produced toothed scales, forming 

 on each side the root of the tail-fin, in a side-view, a pair of distinct, abrupt, and 

 high but sliort keels converging backwards, and meeting in the middle of the fork 

 of the tail-fin. The dorsal and ventral outlines are similar and equal ; and the 

 curvature of each is very trifling throughout ; the truncature of the muzzle and the 

 depth at the root of the tail-fin not requiring much approximation or convergence 

 of the extremities of these lines. The top of the back towards the middle of the 

 body is broad but rounded, becoming flattened towards the head as well as the 

 tail. The belly underneath is rounded : with a fine closed groove, or line, like a 

 cut with a sharp knife, formed by the meeting of the scales of each side the body, 

 and extending from the ventral fins to the vent. Towards the tail the ventral 

 face is flat, or even slightly hollow : with a similar raj)he or groove from the hinder 

 end of the anal fin, becoming obsolete towards the origin of the lower lobe of the 

 caudal fin. 



The greatest depth is from the nape or shoulders to the tips of the pectoral fins ; 

 scarcely diminishing from thence to the origin of the second dorsal or the anal fins : 

 and it is contained from seven to nearly seven and a half times (7-?-) in the whole 

 length of the fish. The thickness, which is greatest at the same part, and de- 

 creases also vmiformly and proportionately with the depth, is three fourths of the 

 depth. The thickness at the origin of the caudal keels or fin is however only one 

 sixth less than the depth at the same place, and is contained nearly thirty times 

 (29-|) in the whole length. The depth at the same point is contained nearly 

 twenty -five times (24f) in the same. The length of the caudal crests or keels 

 themselves equals the diameter of the eyes : their height being one fifth of their 

 length. ^ 



The length of the head is contained little more than four times (4j\ or nearly 

 4-^) in the same : or exactly four times in the length from the tip of the muzzle 

 to the middle of the fork of the caudal fin. It is oblong and four-sided, but 

 deeper than broad ; the sides or cheeks are flat and plain like the top, which is 

 also extremely broad between the eyes ; the breadth here nearly equalling their 

 diameter, which is itself contained between fifteen and sixteen times in the whole 

 length, or a little more than three and a half times (3-j^^) in the length of the 

 head. Hence the eye is very large, occupying considerably more than half the 

 depth of the head ; and though placed a good deal above the middle of the sides, 

 the upper edge of the orbit falls quite within and indeed a little below the profile. 

 It is almost perfectly round, with the edges or orbits peculiarly flat and plain : 

 their hinder half however being crenate, wrinkled, or radiato-striate, like the edge 

 of a sphinctral orifice : reminding one of Vompilus Rondeletii, Will. 



The muzzle is deep, short, and obtuse or truncate ; its length before the eye 

 equalling the diameter of the same. The jaws are of equal length : the upper lip 

 is broad and smooth : the maxillary is externally indistinguishable from the inter- 

 maxillary; and when the mouth is closed, it is in great measure concealed beneath 

 the broad, entire, even-edged anterior suborbitary : its end not appearing at the 

 corners of the commissure or gape. There is no lower lip, at least externally. 

 The anterior nostril is a moderately large, round, simple orifice, situate about one 

 quarter of the distance along an oblique line from the tip of the upper jaw to the 

 upper edge of the eye or orbit : the hinder is a plain lunate slit, a little behind the 

 fore-nostril, along the same line. 



The mouth is large and broad, but the gape is moderate, not extending back 

 beyond the fore edge of the eye : and though the lower jaw is sufficiently extensi- 

 ble, yet the excessive height of its sides quite countervails its mobility, and must 

 prevent the grasp or seizure of any large unyielding substance. 



When closed, nothing appears about the mouth unusual or peculiar : but upon 



