THE MUSEUM 



ATURAL HISTORY. 



ZOOLOGY. 



CLASS IV.— FISHES. 



" Forlliwitb the sounds and seas, each creek and bay 

 With fry innumerable swarm, and shoals 

 Of fish that with their fins and shining scales 

 Glide under the green wave, in sculls * that oft 

 Bank the mid-sea: part single, or with mate 

 Graze the sea-weed their pasture, and through groves 

 C)f coral stray, or sporting with quick glance 

 Show to the sun their wav'd coats dropt with gold, 

 Or in their pearly shells at ease attend 

 IVIoist nutriment, or under rocks their food 

 In jointed armour watch." 



— Milton's Paradise Lost, vii. 399. 



Fishes rank iu the scale of animated beings as the 

 lowest division of Vertebrals. In the preceding pages 

 of this work, the reader has been informed how the 

 massive bony frame-work and other parts of the 

 mammalian structure are modified in the instances of 

 Seals and Cetaceans, to adapt an air-breathing vertebral 

 for an aquatic life ; and also how the Penguins are 

 able to live the life of a fish, through peculiarities of 

 their ornithic constitutions. These and similar facts 

 afford us glimpses of the inexhaustible and admirable 

 methods by which the great Creator has constructed 

 animals for the performance of their special fimctions, 

 yet witliout eOacing the structural type of the particular 

 class to which they belong. The discovery and just 

 appreciation of such instances of creative wisdom, are 

 delightful rewards of zoological study. By the contem- 

 plation of the creatures to which our attention is now 

 to be directed, we perceive, at the outset, that the 

 ponderous bones of terrestrial quadrupeds, or even 

 the much lighter yet firmly knit skeletons of air- 

 cleaving birds, are not essential for animals breath- 

 ing and moving in a medium nearly as heavy as 

 their bodies, which receive no shock in cleaving a 

 way through it with the rapidity of an an-ow. The 

 nature of the medium in which they dwell not only 

 allows great variety in the density of the skeletons of 

 fishes, but also a diversity of external form surpassing 

 anything that has been noticed among the higher 

 groups of Vertebrals, whose aggregate numbers are, 

 ill fact, very inferior to those of the finny tribes, 



* Anglo-Saxon sceole, an assembly. 



whether we look to species or individuals. Some 

 fishes have little or no bony matter in their bodies, 

 and one small fish, occupying the lowest place in the 

 ichthyio scale, is actually destitute of the head and 

 brain, so characteristic of the more highly organized 

 members of the division. 



Using the tena Fishes in the broadest sense in 

 which it is employed by naturalists of the present time, 

 to denote a group of vcrtihrals livino hahituaUy in 

 water, and respiring that fluid during the whole course 

 of their life, and not merely temporarily, like the 

 Amphibians, our purpose is to present such a view of 

 the whole group as may be useful to the student of 

 ichthyology, without overpassing the limits assigned 

 to the subject by tlie projectors of " The Museum." 

 The Natural History of two orders of osseous fishes 

 only, written by Cuvier and Valenciennes, extends to 

 twentj'-two thick octavo volumes;* the work of 

 MUller and Henle on the Sharks and Rays, exceeds 

 two hundred pages folio; f and the admirable lectures 

 of Professor Owen on the Anatomy of Fishes, fill three 

 hundred pages of small type. % Tl'o space allowed to 

 the class in this work will not suflice for more than 

 an attempt to present the characters of the Orders 

 and principal Families, with brief notices of some of 

 the fisheries ; and to add a very few facts evincing 

 intelligence or natural affection in some members of 

 the Class. 



The marine abodes of fish, secluded from continuous 

 observation, limit our knowledge of their habits ; and 

 some kinds that are objects of important and costly 

 fisheries, are known only in that epoch of their exist- 

 ence in which they approach the shores for the 

 purpose of spawning. Several large species residing 

 habitually in deep waters, and coming to the surface 

 under the accidental circumstances merely of injury or 

 disease, have been captured at rare intervals, by seamen 



* Ilistoire Naturelle des Poissons, par M. Le Baron Cuvier 

 et JI. A. Valenciennes An. 1828-1M9. Tom. xxii. A Paris. 



t Beschreibung dcr Plagiostomen, von Dr. J. MiiUer and 

 Dr. J. Henle, 1841. Berlin (60 plates). 



J Lectures on Comp. Anatorav of Vertebrate Animals, hy 

 Richard Owen, F.K.S., 1846. London. 



