PRE FAC E. 



In this work the writers have endeavored to give concise descriptions 

 of all the species of fishes linown to inhabit the waters of North and 

 Middle America. In scope the work includes, therefore, all the species 

 known to exist in North America, Central America, the West Indies, the 

 Caribbean Sea, the Galapagos Archipelago, with the offshore banks and 

 continental slopes of both oceans included, as well as the waters of the 

 Gulf Stream. All marine species known to occur north of the Equator, 

 and all fresh-water species north of the Isthmus of Panama are included. 

 The fact that over a hundred species have been added to the list within 

 the time taken for printing the present volume, shows that this catalogue 

 is still far from complete. 



The classification and sequence of groups adopted by us is essentially 

 that of Dr. Theodore Gill, freely modified to suit our present purposes. 

 This system in many of its details' is purely tentative, to be confirmed 

 or changed when the anatomy of the various forms is better known. 

 This fact has been strongly emphasized by Dr. Gill and needs no further 

 discussion here. In the arrangement of the families and genera we 

 have endeavored to avoid unnatural associations and incoherent groups, 

 even at the risk of what may seem an excessive subdivision. In gen- 

 eral, however, no correct idea of the relation of large groups can be 

 formed until the component parts are separated and defined. 



The rules of nomenclature recently formulated by the American 

 Ornithologists' Union, and now adopted by nearly all American natural- 

 ists, have been followed in this work. The only exceptions are those 

 arising from the operation of two minor regulations which seem to be 

 impracticable or unnecessary.* 



♦The first of these exceptions concerns Canon xvii, 2, which gives to specific names applied 

 to males, precedence over names used for females, when the two occur on the same page. In 

 such cases of synchronous names, we have awarded priority to the name standing first on the 

 page, regardless of other considerations. The other exception is in the rule abandoning a 

 name (as Scaphirhynclum; Xiphidion ; Ctinlhidcrmis) when a prior generic name is of like etymology 

 and of nearly the same spelling (as Scaphorhi/iichim, Xipliiiliiim, or Ai-milliodenna). We regard all 

 generic names as different unless originally spelled alike, and the original orthography (mis- 

 prints aside) is in all cases retained. 



(V) 



