290 THE ZOOLOGIST. 
volumes which he contributed to the ‘Species Général des Lépi- — 
doptéres,’ I cannot recall a single instance in which he has 
suffered structural characters to override superficial; and yet 
each genus and family is prefaced by a careful statement of 
structural points which may readily, nay, is almost certain to be 
mistaken for a diagnosis, until one tries to work with it. For 
example, in characterizing his Geometrid family Acidalide, he 
correctly states ‘“‘indépendante bien marquée aux quatre ailes ; 
costale des inférieures isolée de Ja sous-costale ou simplement 
rapprochée,” of which the equivalent in my terminology would 
be ‘‘ vein 5 well-developed, 8 in the hind wings not connected 
with cell or near base only,” which are really essential characters 
of his genus Acidalia and its allies, and no exceptions are men- 
tioned. Moreover, if the characters given for the Acidalide and 
the Larentide, for instance, are compared throughout, it will be 
seen that there is no absolute distinction between them except in 
the latter of these two characters, the corresponding point for the 
Larentide being ‘‘costale des secondes ailes presque toujours 
bifide,” that is, “8 in the hind wings anastomosing with cell to 
beyond middle.” Now if we proceed to examine the genera 
attributed to the Acidalide, we find the first, Synegia, really has 
5 in the hind wings obsolete, and should therefore be placed (not 
only correctly, but on Guenée’s own definition) in his family 
Boarmide ; the second, Drapetodes, is not a Geometer at all, but 
belongs to the Drepanide, having 5 approximated to 4 in both 
wings; the fifth, Pomasia, and the seventh to tenth, Cambogia, 
Asthena, Hupisteria, Venusia, all have 8 in the hind wings 
anastomosing strongly with the cell, and belong in truth to the 
Larentide. The family definition has in fact been disregarded 
altogether. On the other hand, the characters given for the 
Apamide and Hadenide, for instance, have little reference to 
structure, and are practically identical ; hence it is not surprising 
that species rightly referable to the same genus are placed by 
Guenée, some in one and some in the other of these two families, 
which are separated from one another by four other considerable 
families of Noctue. Now these are not isolated instances, but 
fairly typical examples of the whole work; and yet this classi- 
fication, having been adopted by both Doubleday and Stainton, 
has held the field in Britain for forty years, and has become so 
