ON EMERGENCE OF THE GRYPOCERA AND RHOPALOCERA. 67 
various species of the 41 of peninsular Italyt never ascend the 
mountains, and therefore are absent in the Sibillini (dispar, aragonensis, 
ilia, jasius); three others on the contrary are always limited 
in peninsular Italy to the high mountains, and to only one 
brood (carthami, parthenie, euphrosyne). To the local causes 
mentioned above for the triple-brooded must be ascribed the 
absence of thersamon, idas and liqurica, and the extreme scarcity of 
didyina and phoebe, found once only in August: these specimens had 
the characteristic appearance of II. brood. For phoebe this is explained * 
because the II. brood is specifically the primary one, but in the case of 
didyma, which has a partial summer emergence as a rule even in the 
plain, the phenomenon seems abnormal; of alcetas one 9 of the I. 
brood has been found. It is worth noting that sporadic individuals, 
like these, or aryiolus and aegeria above-mentioned, or aeyeria and 
megera found once only at Valdieri, are nearly always females and bear 
on their wings the signs of a certain age. It will be interesting to 
observe by multiplying the observations, whether there is not found to 
be a migration to some distance of some fecundated females more 
frequently than has hitherto been suspected, and that would explain 
the mysterious disappearance and abundant re-appearance of some 
species in some localities from one year to another. ‘The other 
bigenerate species of peninsular Italy are found in sufficient abundance 
in the valley of Bolognola and can be divided as follows :— 
The 1. brood suppressed : onopordi, armoricanus, carthamt, 
The II. brood suppressed: malvoides, sylvanus, baton, semiargus, 
argus, sebrus, lucina, arcania, maera, cinxia, parthenie, cardiut. 
With two broods: tages, foulquieri, sao, thetis, hylas, thersites, 
iearus, minimus, pamphilus, to, urticae, polychloros, c-album, egea, 
and probably celtis, which was collected in June but which 
seems to behave like some Vanessidi, emerging also in the autumn and 
hybernating. It is to be noted that the suppressed brood is always 
the second brood of the plain, and in many cases is often suppressed 
also in the plain. The only exceptions are maera and cardui; where- 
ever I have collected the first in high mountains I have found that the I. 
brood was primary or only the I. brood existed; the contrary to what 
happens in the plain; as to the second we have in 1917 observed the 
suppression of the II. brood, even in the environs of Florence, there- 
fore this phenomenon does not appear to be related to the altitude. 
We have just remarked that the time of emergence of the I. brood of 
the trigenerates did not at all impede the development of the other 
two broods. With still more reason can we say this of the bigenerates. 
The species which in the plain have a compact emergence in the 
second half of the spring emerge instead in the district of Bolognola 
at the beginning of summer, with about a month’s delay (thetis, 
arcania, maera). The graduated emergence of the plain is shortened 
and becomes compact, so that the beginning is displaced even by 
two months, receding from April to June (tages, malvoides, sao, thersites, 
1The rest of the Italian non-peninsular bigenerates are: orbifer, orion, 
argiades, theophrastus, duponcheli, belemia (Sardinia? if a bigenerate at all!), 
corinna, trivia, selene, levana. The other European species are: marloyi, proto, 
tessellum, cribrellum, ottomanus, amphidamas, fischeri, balcanica, aceris, deione, 
azanthomelas, l-album (II. ?). 
icarus, pamphilus), or from the beginning of May to the end of June 
