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PLAIN BONITO. 
and description are taken; the original specimen being preserved 
in the Museum of the Natural History Society at Penzance. 
It measures eighteen inches in length, and in girth behind 
the first dorsal fin eleven inches and a half. Compared therefore 
with the Mackarel, the body is short and thick, the upper jaw 
short and sharp, gape narrow, under jaw longest, teeth small 
and fine. Eye of moderate size, an inch from the snout, the 
head elevated .above it. Margin of the first gill-cover elliptic, 
gill opening large, an inch and a quarter from the gill-covers. 
Thickness of the body carried far back toward the tail; a corset; 
lateral line crooked, ending in a raised ridge. The first dorsal 
fin in a chink, five inches from the snout, having nine rays, 
of which the two first are closely united and longest, the hinder 
ones very low. Second dorsal and anal small, six inches from 
the first dorsal to the second. The finlets appear to vary, as 
I have a note in which they are eight above and seven below, 
and in another enumeration nine. The caudal fin is propor- 
tionally smaller than in the Mackarel, and the middle rays 
shorter, fifteen in all. Pectoral fins small, not reaching to the 
extent of the corset, stout, and received into a depression: as 
are the ventral fins, and as the depression into which they are 
received is single, they appear to lie beneath a scale. In the 
pectoral fin are twenty-one rays, the ventral six, second dorsal 
seven, and anal eight. 
This fish is not entitled to the name of Plain Bonito, since 
the hack, although generally of a dark blue colour, is also faintly 
marked with marbled lines and ocellated spots; as is also the 
figure given by Cuvier. These, however, had faded in the 
specimen when I examined it 
