SCIENTIFIC SURVEY. ^g 



I will here very cheerfully acknowledge the aid I have received 

 from the published works of Dr. Girard ia his general report before 

 referred to — the late Dr. DeKay on the fishes of New York, and 

 Dr. Storer on the fishes of Massachusetts. Few Ichthyologists 

 describe a fish with more accuracy and precision than Dr. Storer. 

 I have found his description of the color exhibited by different 

 species remarkably correct, and have taken the liberty to often 

 avail myself of this part of his description in this report. I am 

 also under special obligations to Prof. Theodore Gill, of the Smith- 

 sonian Institution, who kindly revised a list of our fishes sent him 

 and furnished information of more sjDecies not yet obtained by me. 

 These, with the proffer of other favors, have been gratefully re- 

 ceived. 



The system of classification devised and promulgated by Prof. 

 Gill and which we propose to follow, is a modification of, and as 

 we think, an essential improvement on that laid down by the cele- 

 brated European Ichthyologist, Johannes Muller. It is based upon 

 the idea, as well as the fact of a gradual rise from a very simple 

 form and frame work of fishes, up to that which is more compli- 

 cated and more perfect in anatomical structure and physiological 

 organization, classifying and arranging them into classes, orders, 

 groups and families step by step, along the whole line as you 

 ascend from base to pinnacle. These are established according to 

 similarity of permanent organs, and the affinities of those subordi- 

 nate parts and appendages which are more variable in form and 

 location. 



To use his own words, " fishes appear to be constructed accord- 

 ing to four diff'erent sub-plans which are characterized by their 

 correspondence to different stages or grades of developement of 

 a typical or model osseous fish " To elucidate this more clearly 

 we will begin at the lowest and simplest form and organization of 

 fishes, as the "Lamper eels" for instance, which exhibit scarcely 

 any organs of a complicated kind or remarkable developement. 

 This sub-class * is called Dermopteri, or skinfins. Their fins, instead 

 of being fitted out with rays and membranes, are merely a duplica- 

 ture or folding over of skin. 



The next step upwards brings us among the sharks and rays, or 

 skates, a class whose frame-work or skeleton, though made up of 



* As Fishes, as a whole, constitute one of the grand classes of the animal king- 

 dom, the next division of them must be into sub-classes. 



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