LEPIDOPTERA. (riod 329 
roll up leaves, &c.), exhibits a decided departure from the typical 
Diurna, and a tendency towards some of the nocturnal Lepidoptera, as 
the Tortrices. Affinities also of a more general nature exist between 
the Papilionidz and Phalenidz. The situation of the genus Ptero- 
phorus, which, according to Réaumur and the Weiner Verzeichniss, 
is to be considered as intermediate between the diurnal and noc- 
turnal Lepidoptera, he does not attempt to determine. With the 
exception, therefore, of the diurnal species, but little progress is here 
made in the classification of the order. <A plan is indeed indicated 
for its natural arrangement ; but it appears to me that the nocturnal 
groups will be found, when more satisfactorily investigated, by no 
means to correspond with these views. 
A more ingenious arrangement of the order has been attempted by 
Mr. Newman in his Essay, “ Sphinx Vespiformis.” | Proceeding upon 
the principle that seven is the typical number of groups in every 
higher group, and that one of these seven groups contains types of all 
the other six, which are arranged around it as a centre, touching its 
circumference by means of aberrant genera — each of the six outer 
circles also coming into contact with the two adjacent circles by 
similar aberrant genera — an arrangement is proposed which certainly 
involves a greater number of affinities than are to be traced in any 
previous classification. His plan of distribution may be learned from 
the diagram shown in next page. 
The same objection appears to me to exist here as in the classifi- 
cations above noticed, namely, that the minor divisions of the noc- 
turnal Lepidoptera are elevated to a rank equivalent to that of the 
whole of the Diurna. 
A more recent author, M. Boisduval, in his Mist. Nat. des Insectes 
Lépidopteres, has obviated this difficulty, by dividing the Lepidoptera 
into only two primary groups, for which, in order to avoid the incor- 
rect notions produced by the terms diurna and nocturna (many of 
the species of the nocturnal Lepidoptera being, in fact, day-fliers), 
he has proposed the names of Rhopalocera (club-horned) for the 
butterflies, and Heterocera (varied-horned) for the moths, including 
the Sphinges, which he does not consider a distinct primary group ; 
and as this appears to me to be an advantageous step, I shall here 
adopt it. ‘ 
