New Forms from the Insect Fauna of the British Coal Measures

Abstract

I. Introduction The present paper contains the results of an examination of a suite of fossil insect wings discovered by Dr. Emily Dix, Prof. A. E. Trueman, Mr. W. Hemingway, and officers of the Geological Survey, to all of whom I would acknowledge my indebtedness for the generous loan of the specimens. The work has been done by means of a Government Research grant from the Royal Society. The specimens comprise about half the series discovered, the remainder including a number of wings whose structure has as yet defied analysis. One species is referred to a family of the Palæodictyoptera, the most archaic group of fossil insects; two others are clearly palæodictyopteroid but, owing to their fragmentary character, cannot be assigned to any known group; three wings are referred to genera of the Protoblattoidea not previously recorded from Great Britain; whilst the list of Blattoidea from British Coal Measures is increased by two new species of the family Archimylacridæ and two species of Mylacridæ. Two forms are referred to the provisional order Hapalopteroidea, hitherto known only from the Anthracitic series of Sharp Mountain Gap, Vermont, Pennsylvania, U.S.A. Five specimens are indeterminable. Diagnosis.—wings twice as long as wide, and thin. Costal margin distally curved inward. Secondary branching abundant, and dividing by regular bifurcation. Diagnosis.—Wings thin, two to three times as long as wide, coastal margin curving inward into a small rounded apex. Inner margin almost straight. Veins branching by regular bifurcation. Diagnosis.— Wings at least two and a half times as