Acantherpestes. Found by Meek and Worth in the coal at Mazon Creek in America (Fig. 46).
Euphoberia. About 12 species found at the same place as the last named.
Amylispes. Found by Scudder, Mazon Creek, America.
Eileticus. Scudder, Mazon Creek, America.
Family 3. Archijulidae.
The dorsal plates nearly consolidated, but the division still apparent. Fossil forms are—
Trichijulus. Scudder, Mazon Creek, America.
Xylobius. Dawson. Found in the coal in Nova Scotia. Two species found at Mazon Creek, America.
Order IV. Chilognatha.
Families corresponding to those of the present day. The oldest specimens come from the chalk in Greenland; most of the others from amber.