PREFACE. VII 



NOTE. lu our descriptions the length of the fish is always measured 

 from the tip of the snout to the end of the last vertebra: the caudal 

 fin being not included. The expressions " head 4" or " depth 4" mean 

 that the length of the head, in the one case, or the greatest depth of the 

 body, in the other, is one-fourth of the length of the fish. "Lat. 1." indi- 

 cates the number of scales in the lateral line; when, however, the num- 

 ber of transverse series of scales between the head and the caudal fin is 

 different from the number pierced by the lateral line we have usually 

 given the former number. The measurements given in the text are 

 intended to apply to mature fishes. Young fishes have usually the 

 depth less, the head larger, the mouth smaller, and the eye larger, than 

 adult examples of the same species. 



In the synonymy of any species, where an author quoted has used the 

 name adopted by us, that name is not repeated. Descriptions not taken 

 from specimens, or at least not verified by us, are, in all cases, credited 

 to the author from whom they have been copied. 



