PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 273 



pace, aud the bases of the fins as well as the lips are encased in tough 

 skin, leathery and flexible. Even the gill-openings are incapable of inde- 

 pendent motion, for they are only straight, narrow, vertical slits in the 

 carapace just in front of the pectoral fins. 



The sinuous muscular movement of the posterior half or two-thirds 

 of the body, which plays so important a part in the movement of the 

 ordinary fish, is of course impossible, and the rotary, sculling motion 

 so noticeable in the caudal fin of a fish, like a minnow or a trout, seems 

 equally unknown. The power of propulsion appears to be vested 

 chiefly in the dorsal and anal fins. These are broad and round, pro- 

 vided ai^parentlj' with strong muscles, and the anal is placed almost 

 directly beneath the dorsal. When the fish moves it is solely by the 

 effect of a strong, slow, regular half-rotary movement of these two ver- 

 tical fins, much resembling that of the screw-wheel of a propeller-en- 

 gine. The caudal fin is kept vertical, and, moved from side to side, plays 

 the part of a rudder, except when needed for an unusually rapid move- 

 ment, and then it adds its strength with long, strenuous side-strokes. 

 There are no ventrq.1 fins, nor do they seem to be needed, for the fish is 

 balanced upon its centre of gravity and well under the control of its 

 I)ropulsive fins. The pectorals probably perform a certain j^art in 

 balancing, but seem to be most useful in keeping up a circulating cur- 

 rent through the gill-apertures. 



Their movements are sluggish, and they do not seem to require a 

 rapid aeration of the blood, for I have known them to live for two or 

 three hours out of water, and when restored seem none the worse for 

 the change of element, save that for a time they were prevented from 

 sinking to the bottom by the air which they had swallowed and which 

 kept them awkwardly suspended at the surface. 



I have rarely seen them swimming among the reefs. They appear 

 to spend most of the time resting on the bottom, on the broad nether 

 surface of the carapace. They never take the hook, but often enter 

 the fish-pots set at a depth of two to ten fathoms. 



'No one has been so fortunate as to observe the breeding habits of the 

 Ostracions ; even the time of spawning is unknown. 



In the Bermudas they are sometimes eaten, though not held in high 

 estimation. I was unable to learn that evil effects ever follow their use 

 for food at this locality. Hollard states that its flesh is said to be ])Sbl-. 

 atable and wholesome, but cites no authority for this observation, 

 which is probably taken second-hand from Lac6p^de, who gives an en- 

 thusiastic eulogy of its good qualities. "Its flesh," wrote the fluent 

 Gaul, "is more sought nfter than that of almost any other fish in the 

 seas of America where it makes its home." And then he continued 

 with a most amusing proposition for acclimating the species in the 

 waters of France, and which is a good example of the theories of the 

 would-be fisli-culturists of eighty years ago. "Although it appears to 

 thrive <m\y in tropical regions we might endeavor to acclimate it in 

 Proc. Nat. Mus. 79 18 Iflarch 25, 1880. 



