SCOLYTIDZA. 81 
Fam. SCOLYTIDA*. 
The species of Scolytide herein recorded from Central America amount to about 
970, equalling one-fourth of the whole number previously described from all parts of 
the World. This total is capable of being greatly enlarged by future workers. 
We have received few Scolytide except from Mr. Champion, and of those collected 
by him a large proportion are unique. Comparatively little knowledge has been 
gained of the Scolytid fauna outside those parts of Guatemala and Panama which 
Mr. Champion visited. An exception, however, must be made in the case of Mexico; 
a moderately large number of Scolytide have been obtained from the collection of 
M. Sallé. These consist chiefly of Platypi, which are of typical value, having all been 
examined and described by Chapuis. 
The habits of Scolytide are very retired, and consequently these insects are difficult 
to collect without special search. More than one-half of the species here enumerated 
(Platypodides, Xylebori, Corthyli, and Gnathotrichus) are known, or may be confidently 
assumed, to be strictly xylophagous and not phlcaophagous ; such insects are hardly 
to be obtained except by chance. M. Grouvelle has forwarded me a large collection 
of Scolytids obtained in Paris from bales of Mexican and Brazilian tobacco. Though 
the original habitat of such specimens is always open to doubt, the collection contains 
numerous remarkable and as yet unknown forms, of which some at least must be 
Mexican. 
A large proportion of unique examples greatly increases the difficulty of studying 
Scolytide. It is sometimes impracticable fully to determine the generic characters 
of obscure forms without dissection and microscopical examination; and this cir- 
cumstance is responsible for the retention as a whole of certain genera of which 
division into two or more parts is desirable, and for the incomplete details which are all 
that can be given about certain species. 
The genera into which these insects fall are either cosmopolitan, as Platypus, 
Hylastes, Hypothenemus, Tomicus, Pityophthorus, Xyleborus, or are of neotropical 
character. Of the latter, some, in the Camptoceri, Bothrosterni, and Corthyli, are 
represented by stragglers in North America, while others, Tesserocerus, Chapuisia, 
Phieoborus, Problechilus, the Hexacolides, Hylocurus, Amphicranus, &c., so far as 
known, are rigidly Neotropical. 
It is likely that the southward limit of many N.-American forms is determined 
* By Watrer F. H. Branprorp. 
BIOL. CENTR.-AMER., Coleopt., Vol. IV. Pt. 6, December 1895. MM 
