GEOGRAPHICAL DISTRIBUTION OF INSECTS. 501 
Leay has an undescribed species from New Holland ; 
and C. retusum was taken in Terra del Fuego. Another 
genus, equally universal and richer in numbers, is the 
lady-bird (Coccinclla), which keeps within due limits the 
Aphides of every climate from pole to pole. The Li- 
hellulina pursue their prey both in Greenland and New 
Holland. The saprophagous carnivora are also similarly 
predominant ;— the Silphidte, the Dermestida?, the Bra- 
chyptera, the Muscida, prey on carcases wherever the 
action of the solar beam causes them to become putrid. 
Many of the above insects have probably their capital 
station, or that where the species are most numerous, in 
or near the tropics ; but the metropolis of the Brachy- 
ptera, at least as far as we can judge from our present 
catalogues, is within the temperate zone, particularly in 
Britain a . The coprophagous Petalocera are most abun- 
dant in the hottest climates ; but the Aphodiadce form a 
predominant group: Professor Hooker took one species 
in Iceland b , and it probably ascends higher ; others are 
found in India and China : but the metropolis of the 
group is within the temperate zone. Perhaps no genus 
is more completely universal than Bombus (Bremus Jur.), 
which, although its centre or metropolis is likewise in 
the northern temperate zone, extends from Melville 
Island to the line. It is remarkable that some of the 
tropical Bombi wear the external aspect of Xylocopce, 
the kindred genus most prevalent in warm climates; and, 
vice versa, some Xylocopce resemble Bombi. I have a 
Brazilian undescribed species of the latter genus, whose 
a Dejean in his catalogue gives only 434 species; while Mr. Ste- 
phens, four years ago, had 550, and has since increased the number 
to above 600. •' Journal of a Tour in Iceland, %J2. 
