iv INTRODUCTION. 
genus, is represented in America north of Mexico by three species, and it would be 
_ premature to assume that both families may not be present. 
Perhaps no tribe of beetles has been more neglected than this one, and therefore 
deductions founded on mere numbers of species as given in our catalogues cannot be 
considered of great value. A reference to the proportion of species enumerated in this 
volume to those given in Gemminger and Harold’s Catalogue will make this obvious. 
Of all the families here united under the Malacodermata the known species amount 
to but 3530, while from Central America alone we here record 813 species, contained 
in 120 genera, of which no less than 535 species and 28 genera are now described, as 
it is believed, for the first time. | 
The only regions of which our knowledge of these insects was more complete than 
of Central America previous to the publication of this work were the United States 
portion of the Nearctic, and the Palearctic region, exclusive of Asia generally. It is 
now seen that the Tropical portions of the earth are as rich, or richer, in these groups 
than the cooler parts, not only from the collections which have come to the Editors, 
but from other evidence before me from other districts. Hence, if we simply calculate 
by the percentage of new species to those already described, and if we exclude from 
our calculation the European species (which numbered 1151 in Marseul’s Catalogue of 
1866), and those of North America (508 in Crotch’s Check List of 1874), as having 
been better investigated, we shall find, in a rough way, that if the species of this tribe 
from the rest of the world were only collected and described to the same extent as is 
here done for Central America, the whole number could not amount to less than 9500. 
And considering the numbers that have been, and are still being yearly, added to the 
European and North-American lists, I think we shall be much within the mark in 
assuming that there exist not less than 12,000 species of this section of the Coleoptera. 
With respect to the distribution of the 120 genera to which the Central-American 
species are referred, any generalization drawn from the whole number would be very 
much invalidated by the consideration that the work of differentiation has at present 
only been fairly begun in the Lycide, the Telephoride, the Melyride, the Ptinide, 
and the Bostrychide (it is more advanced in the Lampyride and Cleride), and it 
is chiefly in these families that it has been found necessary to propose new genera. 
Of these I observe that, with three or four exceptions, the few species which can 
be associated with them from other parts are about in equal numbers from North 
and South America. But in the families in which I have not found it necessary to 
