INTRODUCTION. xxx j 



Gunther's Catalogue of the Fishes of the British Museum, the first five volumes, 1859-1865; 

 Dumeiul, Ichthyologie ginirale, volume the first, 18G5. 



Before commencing the individual descriptions, a few explanatory remarks are requisite on 

 the mode adopted in taking measurements, &c. 



Roman figures are employed to designate the number of the branchiostegous rays : also the 

 Unlets, as in the Caranx Rottieri, &c, or elongated free rays, as appendages to the pectoral fins 

 in the Polynemi; an exceptional case being in the Bregmaceros Macclellandi, in which it is im- 

 possible to give the various portions of the fins distinctly without using these figures. 

 O signifies an adipose fin. 



In counting the number of rays, when two arise from one interneural or interhmmal spine, as 

 frequently takes place in the last of the dorsal and anal fins, they are reckoned as one, a plan 

 sanctioned by high authorities, but open to objection and not adopted by Dr. Bleeker. In the 

 caudal fin the small outer rays are not included. The horizontal procumbent spine which exists in 

 many genera before the base of the dorsal fin is not included in the formulary, neither is the short 

 vertical bone before the dorsal spine in many of the siluroids. 



By L. I. is meant the number of pierced scales, extending from the shoulder bones to the 

 base of the caudal fin. By L. r. the numbers of rows of scales passing downwards from the back 

 to the lateral line along its whole extent. By L. tr. the number of scales in a row passing down- 

 wards from the origin of the dorsal fin to the lateral line, and between the lateral fine and the 

 abdomen. In speaking of the lateral line of mullets, the term is only used for convenience of 

 description, as it is absent. 



By the total length, is meant that included between the end of the snout and the centre of 

 the termination of the caudal fin, unless otherwise stated, as in the Fistularia serrata, in which 

 the two central rays are produced into long filaments. 



By the length of the head, is commonly meant from the anterior end of the jaws when closed 

 to the posterior extremity of the bony opercle; to this several exceptions exist, as in the Alutarius 

 Icevis, in which the eye and much of the skull is behind that situation, whilst in the Hemiramphus 

 the lower jaw is extended in the form of a beak far beyond the mouth. 



By the length of the snout, is meant the distance between the anterior margin of the orbit 

 and the centre of the intermaxillaries, unless otherwise stated, as in the Genus Belone. 



By the length of the base of a fin, as the dorsal, is meant the distance between the base of its 

 foremost to that of its hindermost spine or ray, except in those genera which have a procumbent 

 horizontal spine before them, which is not included. 



By the length of a fin is meant its extreme length even when it is prolonged, thus in the 

 Polyacanthus cupanus the pectoral is given to the end of its filament. 



By the height of a fin is meant the length of its longest spine or ray, unless otherwise 

 expressed. 



