38 



propose and which I have used in the following descriptions, I 

 have to subject to criticism the systems which have been so far used. 



Concerning the indication of the setae by means of cyphers, as 

 used by W. Muller (1886), Dyar (1894 and 1901), Quail 

 (1904 and 1904 b), Forbes (1911), these writers have made so many 

 changes, that it would be a hopeless task to try to improve it. 



Fracker has grouped together the opinions of the different 

 investigators into a table (1. c. p. 40). For a single slight mo- 

 dification I wish to quote a striking case from it. Quail indicates 

 the large seta over the stigma with III or III A and the small 

 one in front of it with III B, and not as Fracker does : with III 

 and III A respectively. If we look at the seta over the stigma on 

 the abdomen, we see that it has been named in the following ways : 



Mesothorax and Metathorax (Frenatae). 



Muller 1886, Dyar 1895, Hofmann 1898, Dyar 1901, Quail 1904, Forbes 1910. 

 4. lib. IV. IV. III. * II B. 



Abdomen. 



Muller 1886, Dyar 1895, Hofmann 1898, Dyar 1901, Quail 1904, Forbes1910. 

 3. III. III. III. Ill A. III. 



So, whilst on the abdomen at least all the writers have given 

 the same cypher to this seta, Fracker considers it to be p, to 

 which in Hepialus the others certainly would not have given 

 this index, as p belongs to the caudal row, and the abdominal 

 seta III has been placed by the majority of writers in the oral 

 row. Anyone can find other examples from the figures placed 

 side by side on PI. I. 



Tsou's system I have already discussed. Of the systems in 

 which no names are used, that of Fracker is the most important, 

 and against this system I have serious objections. 



In the first place Fracker's method of concentrating all the 

 setae occurring on the several segments of different larvae into 

 one segment and of declaring this hypothetical segment to be the 

 original form, is wrong. 



For it is probable that a certain organ of a given original 



