4 INTRODUCTION 
position of the species thereon, thus [43-18], against No. 162 of the 
basic list, indicates that Histiophorus herschelu, the 18th species on 
page 43 of the “Index” is herein referred to as Tetrapturus indicus. 
While species are natural, though mutable, genera are largely 
artificial and subject to the personal views of the investigator ; it 
follows, therefore, that in time an approach will be made to a 
thorough knowledge of the species, by the discovery of new, and 
the elimination of nominal forms: zoologists are not, however, likely 
to agree in respect to genera, except by mutual arrangement, and it 
is to be noted that this list is intended merely as a basis for future 
zoological or systematic research. 
Care has been taken in the matter of authorities and dates. An 
accurate reference to the original description of the species has been 
the chief aim; the genus with which each was first associated, and 
that with which it is now indentified is given, and also the author 
and date of modern genera. 
The Selacians are arranged according to the recent classification 
of Mr C. Tate Regan,” the Teleosteans mainly on that proposed by 
by Dr. G. A. Boulenger,* but the writer is not in full accord with 
the nomenclature respectively used. The writings of American 
Ichthyologists have been freely consulted, especially those of 
Dr. Gill, Dr. Jordan and his colleagues, also Drs. Evermann, Fowler, 
and Gilbert. 
K. R. W. 
15th March 1907. 
2. Regan, Proc. Zool. Soc. 196, p. 722. 
3. Boulenger, Cambr. Nat. Hist. VII., 1904. 
