Excerpt from The Hope Reports, Vol. 8: Appendix 1890-1910, Including Five Subfamilies of the Blattidae

The tegmina overlap to a greater or less extent; they are horny, coriaceous or membranoug: in the genus Diaflza/za they are entirely membranous and transparent, in the genus Holorompsa the basal half is coriaceous and opaque, the apical half membranous and transparent, producing the appearance of the tegmen ofa Heteropterous bug. Occasionally the tegmina are ciliated (polyfi/mga, Corydz'a) or covered with a sericeous pile (nye/ibom, Parana/firs). Four main nervures or veins issuing from the base of the tegmen may be distinguished, viz I. The mediastinal vein, which runs to the anterior border of the tegmen before its middle; the part of the tegmen between its anterior bordei and the mediastinal vein is known as the mediastinal area; branches or secondary veins are emitted bv the mediastinal vein only towards the anterior border. 2. The radial vein extends to the apex of the tegmen dividing it into two more or less unequal parts, the marginal area and the discoidal area; in some genera the marginal area is almost equal in breadth to the discoidal area, in others it is a narrow strip; branches are given off to the anterior margin of the tegmen (costal veins) and sometimes to the apex. 3. The ulnar or median vein gives off a number of branches to the apex and to the sutural margin of the tegmen, when these branches unite in two main trunks thev are termed the anterior ulnar or interno median and the posterior ulnar or externo-median, 4. The anal vein runs in a curved line to the sutural margin at a point before its middle: it is usually well-marked and sometimes impressed: the part of the tegmen enclosed bv it is the anal area, and IS occupied by a series of more or less parallel secondary veins, known as the axillan veins, whose number ranges from three to twelve or more. These four main nervures are generally distinct, but in tegmina of corneous texture they tend to disappear; the secondary veins more frequently become obliterated.

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.