PREFACE. 



The Fourth of the Series of First-Books of Natural History, treats of 

 Reptiles and Fishes, two classes of the Animal Kingdom, which are vastly 

 useful to man, affording him inexhaustible supplies of excellent food. Be- 

 sides being useful, they are deeply interesting in a physiological point oi 

 view, illustrating as they do, in their ecpnomy, many of the important vital 

 functions of our own organization. In them we see how the allwise, and 

 benevolent Creator has wonderfully adapted their structure to the circum- 

 stances under which they were destined to breathe, and have their being ; 

 and at almost every step we might pause to admire the surpassing wisdom 

 of Him who made them such, and bow down in gratitude for the bounties 

 showered upon us, every where in this boundless and beautiful creation. 

 But had we given place to reflections of this nature in the course of our 

 little work, we should have far exceeded our limits, and probably obscured 

 the sketch we wished to draw clear and intelligible. 



Some objection may be made perhaps to the systematic names and tech- 

 nical words, which have been necessarily used without immediate explana- 

 tion. To meet this difficulty, a copious glossary, with the etymologies and 

 pronounciation of the words, has been added, which will facilitate the young 

 reader, and prepare the way to more extensive reading on the subject. It 

 will be seen that many of the words which have been explained in the 

 glossaries of preceding books of the series, are also found in the present 

 volume. This repetition renders each book, to a considerable extent, 

 available by itself, and obviates the necessity of recurring from one to the 

 other for the explanation of words. All persons who are desirous of acquiring 

 a knowledge of Natural History, are not acquainted with the Latin and 

 Greek languages ; therefore, the words from the latter have been printed in 

 italics, in preference to using the proper Greek characters, and the omega, 

 where it occurs has been designated thus, 6. 



As in the preceding volumes, I have not confined myself exclusively to 

 the works of MM. Edwards and Cornte, the chief sources from which the 

 materials of these Primers have been derived ; but I have freely availed 

 myself also of the labours of Cuvier, T. Rymer Jones, and others. 



It is not designed that the questions at the foot of the page shall be 

 answered by repeating the text from memory ; the pupil should be able to 

 give the facts in his own language, and sliow he understands the subject. 



The plates were engraved by Mr. G. Thomas, No. 37 South Third Street, 

 Philadelphia. 



Philadelphia, July, 1842 



