FISHES. 189 



South Carolina, and it occurs occasionally nearly as far north as Cape Cod, a number 

 of specimens having been obtained at Woods' IIoll ; but it is chiefly young that have 

 been seen north, the old being very sj)aringly represented. On the Gulf coast it is 

 ([uite common, and is considered to be the choicest fish of the sea; a great commercial 

 demand exists for it, which is fully supplied for only a few weeks in the year — in the 

 spring and early summer. Along Florida, in the southern part, it is fovmd through- 

 out the year; but in the northern j>art it arrives on the coast in spring, and goes 

 away from it in the fall. The movements of the fish are from the eastward, and they 

 swim as near to the shore as the state of the water will permit ; very seldom at the 

 surface so as to ripple or break the water, although sometimes, while playing in shal- 

 low water, they will jump into the air. Its food seems to consist mainly of small 

 shell-fish, which are sujiposed to be crushed between the pharyngeal bones. At Key 

 West the pompano is caught in considerable numbers by hook and line. 



The pompanos manifest great differences according to age. The old form has 

 already been adverted to, especially in reference to the short spines unconnected by 

 membrane, and the anterior rays of the dorsal and anal fins. In this condition, when 

 very old, they arc destitute of teeth in the jaws, and even on the pharyngeal bones. 

 When they are very young, and of minute size, the s])ines of the first dorsal are well 

 developed, and connected to form a true fin ; the anterior rays of the second dorsal 

 and anal are comparatively short ; the teeth are developed in the jaws and pharyn- 

 geal bones, and the preoperculum is armed with several radiating spines. As the fish 

 grows in size, first the preopercular sjiines are lost, then the membrane between the 

 dorsal spines becomes reduced, and finally atrophied ; meanwhile the dorsal and anal 

 rays in front become elongated, and lastly the teeth are lost from the jaws and pha- 

 ryngeal bones. The different stages of growth represented by these two extremes, 

 and the intermediate ones, have given rise to several nominal genera. 



The celebrated pilot-fish, Naucrates ductor, represents another group of Caran- 

 gidae, and is distinguished by its handsome and symmetrical fusiform shape, the de- 

 velopment of about four spines unconnected by membrane, in place of a dorsal fin, 

 and the existence of transverse black bars on a bluish ground. Tiie species is almost 

 cosmopolitan in distribution, but as a pelagic species, for it rarely comes close in 

 shore. It does not often attain the length of much abo\e a foot. The name of pilot- 

 fish is derived froin a supjtosed relation to sharks, with one of which it is generally 

 found in company. According to Dr. Meyei', the pilot swims constantly in front of 

 the shark, and he saw several instances in which the shark was led by its small com- 

 panion. " When the sea-angel neared the ship, the pilot swam close to the snout, or 

 near one of the breast fins of the animal. Sometimes he darted rajndly forwards 

 or sidewards, as if looking for something, and constantly went back again to the 

 shai-k." On another occasion, when a large hook, baited with a piece of bacon, was 

 thrown overboard, the "shark was about twenty paces from the sbij). With the quick- 

 ness of lightning the pilot came up, smelt at the dainty, and instantly swam back 

 again to the shark, swimming many times round his snout, and splashing, as if to give 

 him exact information as to the bacon. The shark now began to j>ut himself in mo- 

 tion, the pilot showing him the way, and in a moment he was fast u])on the hook." 

 On a later occasion, two pilots were observed in assiduous attention on a blue shark. 

 " It seems probable that the pilot feeds on the shark's excrements, keeps his company 

 for that pur]»ose, and directs his operations solely from this selfish view." 



Like the pompano, the pilot-fish exhibits considerable variations with age ; when 



