CHAP. XV.] 
THE NEARCTIC REGION. 
12S 
forms. A considerable number of Neotropical types enter the 
southern States; but there are hardly any peculiar genera, except 
one of the Lycaenidae and perhaps a few among the Hesperidae. 
The most conspicuous feature of the region is its fine group of 
Papilios, belonging to types (P. turnus and P. troilus ) which are 
characteristically Nearctic. It is also as rich as the Palaearctic 
region in some genera which we are accustomed to consider 
as pre-eminently European ; such as Argynnis , Melitcea , Gmpta, 
Chionabas, and a few others. Still, we must acknowledge, that 
if we formed our conclusions from the butterflies alone, we could 
hardly separate the Nearctic from the Pakearctic region. This 
identity probably dates from the Miocene period ; for when our 
existing arctic regions supported a luxuriant vegetation, butterflies 
would have been plentiful ; and as the cold came on, these would 
move southwards both in America and Europe, and, owing to the 
long continuance of the generic types of insects, would remain 
little modified till now. 
Goleoptera. — Only a few indications can be given of the 
peculiarities of the Nearctic coleoptera. In Cicindelidse the 
region possesses, besides the cosmopolite Cicindela, four other 
genera, two of which — Amblychile and Omus — are peculiar to 
the West Coast and the Rocky Mountains. Of Carabidse it 
possesses Diccelus , Pasimachus , Eurytrichus , Sphceroderus, Pina- 
codera , and a number of smaller genera, altogether peculiar to it ; 
Helluomorpha, Galerita, Gallida, and Tetragonoderws, in common 
with South America ; and a large number of characteristic 
Eutopean forms. 
The Lucanidse are all of European types. The region is poor 
in Cetoniidae, but has representatives of the South American 
Euphoria , as we-ll as of four European genera. Of Buprestidse 
it has the South American Actenodes ; a single species of the 
Ethiopian and Eastern Belionota , in California ; and about a 
dozen other genera of European and wide distribution. 
Among Longicorns it possesses fifty-nine peculiar genera, 
representatives of five Neotropical, and thirteen Palaearctic genera ; 
as well as many of wider distribution. Priomis is the chief 
representative of the Prionidse ; Leptum and Grossidius of the 
