﻿STRUCTURE 



539 



The anterior 



In the females of numerous Heteroptera and Homoptera 

 (Capsidae, Cicadidae, etc.) there is a well-developed ovipositor, that 

 serves both as a cutting instrument to make slits in the stems 

 of plants, and as a director to introduce the eggs therein. Yerhoeff 

 considers that it always consists of two pairs of processes (though 

 one pair may be very small), one from the eighth abdominal 

 segment, the other from the ninth. 1 



The antennae usually have very few joints, often as few as 

 four or five, their maximum number of about twenty-five being 

 attained in the males of some Coccidae, this condition being, 

 however, present in but few of even this family. In Bdostoma 

 (Fig. 279) they assume extremely curious forms, analogous to 

 what we find in the Coleopterous genus Hydrophilus. In addi- 

 tion to the compound eyes, there are usually ocelli, either two or 

 three in number, but wanting in many cases. The usual number 

 of joints of the tarsi is three, but in Coccidae. there is only one 

 joint. 



The wings (Fig. 258) exhibit much diversity, 

 pair usually differ greatly from, the pos- 

 terior ; they are called elytra, hemi-elytra 

 or tegmina. This difference in the two 

 pairs is the rule in the first of the great 

 divisions of the Order, and the name 

 Heteroptera is derived from the fact. In 

 this Sub-Order the front wings close over 

 the back, and are more or less horny, the 

 apical part being, however, membranous. 

 Systematists make use of the wings for 

 the purpose of classification in Heterop- 

 tera, and distinguish the following parts, 

 " clavus," " corium," " membrane," the B 



eorium being the larger horny division, Fig. 258.— Alar organs of a 

 the clavus the part lying next the scu- %% ^^ntt 

 tellum and frequently very sharply dis- clavus •. b, corium ; c, 



, • ■ i i f. ,i • .-i cuueus ; D. membrane ; 



tmguished trom the corium; the mem- E> Ej cell of the I1R . m _ 

 brane is the apical part. The outer brane ; B, hmd-wmg. 

 or costal part of the wing is also often 



sharply delimited, and is called the " embolium ; " in the great 



family Capsidae and a few others, the outer apical part of the 



1 Eat. Naehr. xix. 1893, \>. 375. 



