204 



LOWER VERTEBRATES. 



of only a few short ribs; the Boft fins are also peculiar m being so ^^e^ ^^ 

 the skin as to leave the rays almoet mdistinguishable, and to remmd one of the fin o 

 sharks rather than those of ordinary fishes. It is the object of extensive fishenes 

 both in the Mediterranean and along the New England coasts, and has been made 

 the subject of an elaborate report by Professor Goode, which furnishes us with some 

 nte estin. data. From time immemorial it has been known to the dwellers around 

 the Mekrranean, where it is quite common; and individuals occur in summer bu 

 more and more sparingly as they approach the north even as ^^f - f ^^^ 

 and along the American coast it advances northward at least as far '^ ^f ^J j* ^ 

 likewise found in the Pacific, and ha^ been recognized along the coast of Califoinia, 



Fig. in.—Histioplu>rus gladius, sail-flsh, adult. 



and in the southern hemisphere its presence about New Zealand has been recorded 

 Its appearance seems to be determined chiefly by temperature, and it is generally first 

 seen on the coast from New Jersey to New England about the last of May or early m 

 June and remains in those waters until September, or when the first cold wmds drive 

 it off It is said to be seen only on quiet summer days in the morning before ten or 

 eleven o'clock, and in the afternoons about four o'clock, and fishermen say that it rises 

 when the mackerel rise, and when the mackerel go down the sword-fish also goes down. 

 When tbey first appear, the fishes are very poor and lean, but as the summer advances 

 they grow fat The first are comparatively of small size, averagmg about one hun- 

 dred and fifty pounds gross, and of a length measuring about four feet ; but later and 



