106 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 back, 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. 



