( cxxxvi ) 



ducing a similar division into such genera as Tachi/ris, Euchloe, 

 Synchloe, and Teracolus proper itself. Facts such as these 

 prove that too much dependence must not be placed on the 

 presence or absence of the plume-scales as evidence of affinity. 

 Nevertheless, it is quite certain that, if conducted with due 

 discrimination, the examination of the occurrence, and still 

 more the character, of these organs is capable of giving 

 valuable assistance in the way of confirming or correcting the 

 conclusions arrived at from other sources. 



Thus, we have seen that the genus Dajotonura is shown by 

 the unique character of its plume-scales to be really a natural 

 group ; and on the same evidence we must pause before we 

 consider it to be so nearly allied to Belenois as on the strength 

 of other characters we might be tempted to suJT^wse. Again, 

 no assemblage could be more clearly marked out as closely 

 related among its own members, and isolated from all other 

 forms, than is the African section of Mylothris by its very 

 peculiar scent-scales. On the like evidence we perceive that 

 the resemblance boine to the African by the American species 

 of that genus in the matter of neuration is merely superficial ; 

 and that the true affinities of the so-called American Mylothris 

 are with a certain section of another genus, the so-called Pieris, 

 inhabiting the same zoological region with itself. 



The obvious resemblance between such forms as Euchloe 

 cardamines $ and Synchloe daplidice suggests that in spite of 

 certain differences in neuration these two genera must be 

 closely allied. This suggestion is quite borne out by the 

 characters of their respective scent-scales ; and a further 

 examination of the same structures indicates that there is no 

 very near relationship between Synchloe and the groups 

 represented by Ganoris rajMe, napi and brassicae. 



It has already been pointed out that the three recognised 

 sections of Urania, viz. Kepheronia, Leuceronia, and Eronia 

 proper, are easily distinguishable by their scent-scales ; a kind 

 of bridge between the first two sections being afforded by 

 Nepheronia avatar and Leuceronia thalassina. In this, as in 

 many other Pierine assemblages, it is noticeable that specific 

 distinctions between the plume-scales, though nearly always 

 present and recognisable, are often very slight ; that the 



