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mental effects. He instanced many Japanese species, which 

 were almost, or exactly, identical with our British species. 



Mr. Tutt said that in the Palasarctic Region there were 

 many groups of species, composed of very closely allied and 

 sometimes almost indistinguishable individual species, and 

 instanced the Anthrocerids (Zygsenids) of Europe, which 

 might be termed one species or many according to the 

 student's particular point of view. He considered the 

 naming of the various forms was a matter of convenience, 

 and a necessity for study, reference and inter-communication. 

 The present plan of lumping recently adopted by the British 

 Museum authorities he strongly condemned. With regard 

 to P. comma, he stated that it was in England a remarkably 

 stable species in its variation, whereas on the Continent it 

 showed a very considerable range of variation at different 

 altitudes. It did, however, vary in this country, but the 

 aberrations were few and rare. In North America, however, 

 this species attained its extreme of variation, for it formed as 

 it were a centre, around which many local races and weak 

 species were grouped. L. argiohis represented in North 

 America by L. pscudargiolus he regarded in a similar light to 

 the last species, as showing like characteristics tending to 

 produce more or less well-defined specific forms. 



Mr. Montgomery exhibited a long series of Pievis napi, 

 and read the following notes : 



" The specimens in the first four rows are selected from 

 twenty males and twenty-two females, which emerged 

 between April 21st and May 14th, 1897, and seventeen 

 males and eleven females, which emerged between July 4th 

 and 7th, 1896 ; all these are the progeny of one female taken 

 at Harefield. Middlesex, May 25th, 1896. They may be 

 taken as typical of the seasonal dimorphism of the species 

 in the home counties. 



"The examples in the next two rows are from twenty-two 

 males and eighteen females, the result of forty eggs deposited 

 by a female received alive from Enniskillen on June 14th, 

 1897, and which emerged between May 4th and 17th, 1898. 

 These specimens do not seem to vary to an appreciable 

 degree from the spring specimens of Harefield parentage. 

 They are somewhat larger, which may be the result of a 

 change of food-plant and a more roomy cage, and the 

 males are on the whole better marked, the palest being 

 equivalent to the darkest Harefield male. The females 

 appear to be identical, and it will be noticed, by com- 

 paring them with the captured female, that they have 



