350 
ZOOLOGICAL LITERATURE. 
general statement^ and at the same time remarks that as so 
great a proportion of the Coleoptera live, either in the larva or 
perfect state, in the wood or beneath the bark of trees, the ex- 
ceptional distribution of the insects of this order in the eastern 
islands may be accounted for by their transportation from island 
to island in floating timber &c. In the case of Lepidoptera, 
this cause of diffusion of species can hardly exist ; and although 
these insects are liable to be carried to great distances by storms 
and by the monsoons, their chance of establishing themselves 
in new islands is greatly limited, among other things, by the 
necessity which so many of them labour under of finding the 
proper food-plant of their larvie in their new home. In illus- 
tration of this view, Wallace here investigates in detail the Bie- 
rides of the combined Indian and Australian regions, paying- 
particular attention to the geographical range of the species, 
which is well represented in a series of tables occupying pp. 402- 
41 5. From the author’s statements it appears that not only species, 
but genera and sections of genera are characteristic of the islands 
on one side or the other of his line of demarcation above referred 
to ; and the facts in general are considered by him to confirm 
his view that the islands situated to the east of this line belong 
to the Australian, and not to the Indian region. Wallace further 
discusses the distribution of the species and the number of pecu- 
liar species in the different islands and groups of islands, and 
remarks that (as also in the case of the true Papilionides) Ce- 
lebes presents a great amount of peculiarity. The Fierides of 
Celebes likewise present a peculiar subfalcate form of the ante- 
rior wings. Examples of mimicry are not numerous or stri- 
king among the eastern Fierides \ but Wallace refers to some 
examples of this phenomenon presented by them (pp. 309- 
3II). 
Wallace discusses the generic characters presented by the 
Fierides (pp. 3I2-3I4) . He adopts the genus Thyca (Wallengr.) 
to which he refers 57 species, and gives the following table 
(p. 314) showing the distinctive characters of that genus, and of 
2 new genera which he has established at the expense of the 
genus Pieris of authors : — 
A. One branch of subcostal before end of cell Thyca (Wtillengr.) 
AA. Two branches of subcostal before end of cell. 
B. Males with tufts of hairs or bristles at anal valves. 
Tachyris, g. n. 
BB. Males with anal valves bare. 
0. Males with costa serrated Prionebis, g. n. 
CO. Males with costa smooth Pieris. 
The following specific synonyms are indicated by Wallace (and others will 
be found in the list of species belonging to his new genera) ; — Pieris pallene 
(Hew.)=^/oc?ma angulipmnis (Luc.); Teriaszama (Feld.)= $ T. zita (Feld.); 
2\ iondana (Feld,)=^ommea (Voll.) ; Pieris ivallacema (Feld.)= $ rachel 
