18 
ZOOLOGICAL GEOGRAPHY, 
[part. hi. 
Macrodontia ; and Titanus , the largest insect of the entire 
family. 
Of the Cerambycidse there are 233 genera, exceeding by one- 
half, the nnmber in any other region; and 225 of these are 
peculiar. Only 2 are common to the Neotropical and Nearctic 
regions exclusively, and 3 to the Neotropical and Australian. 
The most extensive genera are the elegant IUdion (80 sp.) ; 
the richly-coloured Ghrysoprasis (47 sp.); the prettily-marked 
Trachyderes (53 sp.) ; with Odontoeem (25 sp.); Criodon (22 sp.) ; 
and a host of others of less extent, but often of surpassing 
interest and beauty. The noteworthy genera of wide range are, 
Oeme and Cyrtomerus, which have each a species in West Africa, 
and Hammatoccrus, which has one in Australia. 
The Lamiidse have 219 genera, and this is the only tropical 
region in which they do not exceed the Cerambycidse. This 
number is almost exactly the same as that of the Oriental 
genera, but here there are more peculiar groups, 203 against 160 
in the other region. The most extensive genera are Hemilophus 
(80 sp.), Colobothea (70 sp.), Acanthoderes (56 sp.), Oncoderes 
(48 sp.), Lepturgus (40 sp.), Hypsioma (32 sp.), and Tamiotes 
(20 sp.). Macropus longimanus , commonly called the harlequin 
beetle, is one of the largest and most singularly-marked insects 
in the whole family. Leptostylus has a single species in New 
Zealand; Acanthoderes has one species in Europe, W. Africa, 
and Australia, respectively; Spalacopsis has a species in W. 
Africa ; Pachypeza is common to S. America and the Philip- 
pines ; Mesosa is Oriental and Palaearctic, but has one species on 
the Amazon ; Apomecyna ranges through the tropics of the 
Eastern Hemisphere, but has two species in S. America ; Acan- 
thocinus has one species in Tasmania, and the rest in South 
America, North America, and Europe; Pima is wholly Neo- 
tropical, except two species in the Philippine Islands. 
General Conclusions as to the Neotropical Insect-fauna . — 
Looking at the insects of the Neotropical region as a whole, we 
are struck with the vast amount of specialty they present ; and, 
considering how many causes there are which must lead to the 
dispersal of insects, the number of its groups which are scattered 
