GENERA AND SPECIES. 79 



This mighty gathering of fishes not exceeding three inches long 

 remained about Polperro for a week and then disappeared, not even 

 a straggler having been since. The few that were caught have 7 or 

 8 spines in the first dorsal, a spine and n or 12 rays in the second 

 dorsal, a spine and 12, 13, or 14 rays in the anal, and 17 rays in the 

 caudal ; in the pectorals there are 14 or 15 rays, and in the ventrals 

 are a spine and 5 rays. The lateral line has from 50 to 57 scales. 

 The mouth is cleft very obliquely, and extends to the front edge of 

 the eye, the eye being much larger than that of the common 

 Atherine. 



Auxis. Plate vi. SCOMBRID&. 

 43. rochci. PLAIN BONITO. Dorsals re mote ; first dorsal triangular. 



The first dorsal is triangular and has 10 or n rays, the second 

 dorsal is as far removed from it as the base of the triangle is long, 

 and has n or 12 rays, and behind it are 8 or 9 finlets; the anal has 

 ii or 12 rays followed by 7 finlets; the caudal has 24 rays ; in the 

 pectorals are 21 or 22 rays, and the ventrals have the usual spine 

 and fin rays. The ventrals are beneath the pectorals, and the anal 

 starts below the first finlet. The lateral line becomes crooked above 

 the anal fin. There are 3 keels at the base of the caudal, and pro- 

 longations to the corslet. The mouth extends to the middle of the 

 eye ; the teeth in the jaws are small, and there are none on the 

 palatines and tongue. In colour this bonito is bluish, with silvery 

 underparts. In size it measures about 18 inches. It is rare in 

 British waters. 



Balistes. Plate xv. BALISTID&. 



120. maculatus, TRIGGER FISH. Side spotted ; no plates behind gills 



121. capriscus, FILE FISH. Side not spotted ; two plates behind gills. 



The Trigger-fish has 3 spines in its first dorsal, 26 or 27 rays in 

 its second dorsal, 24 or 25 rays in its anal, and 12 in its caudal ; in 

 its pectorals there are 15 rays, and the ventrals are represented by 

 a movable bony knob. The dorsal spines are black and at equal 

 intervals, and the front one is longer and stronger than the others. 

 The scales are rough and granulated, and form a carapace. The 

 colour is blackish, and the length is about 16 inches. The species 

 is very rare in our home seas, in fact it is doubtful if it has been 

 caught more than once. 



The File Fish is not quite so rare. In its first dorsal there are 

 3 spines, and in the second 27 or 28 rays ; in its anal there are from 

 24 to 26 rays, and in its caudal 12 rays; there are 15 rays in its 

 pectorals, and the ventrals are represented by a bony process as in 

 the other species. The first spine is the longest, and the second is 

 not so far from it as from the third. The scales form a carapace. 

 The colour is yellowish, darker on the upper portion ; the size is 

 about 16 inches. The generic name is derived from the way in 

 which the spines spring up when raising the fin. Like the preced- 

 ing species it is a native of the tropical seas, where it feeds on corals 

 and hard-shelled mollusca. 



