ORTHOPTERA. 
213 
radical joint in their enumeration, while others have 
overlooked it, or regarded it merely as a point of 
support to the palpus. Although frequently almost 
lost in the substance of the labium, this joint appears 
however to he always present, and although ap- 
parently three-jointed, the palpi must therefore be 
regarded as really composed of four articulations, 
(Plate VI. fig. 6, c, c.) 
The tongue, ( lingua ,) generally a very obscure 
member of the oral appendages, is very distinct in 
some of the insects of this order. It is short, re- 
tracted within the mouth, rather of a soft substance, 
and in some instances, as in Blatta and Locusta, it 
bears a pretty close resemblance to the tongue of a 
vertebrate animal. 
The modifications of the antennae will be specified 
afterwards as aiding in the discrimination of the 
different groups. In general they are long, setace- 
ous, and extremely flexible, consisting of fourteen, 
sixteen, or twenty-five joints among different species 
of Locustae ; of above thirty among the Mantes ; 
while in the Blattee or Cockroaches, the articulations 
sometimes amount to 150, and vary even in indivi- 
duals of the same species. 
Besides the ordinary compound eyes, which in 
general are large and prominent, the insects of this 
order are mostly provided with three simple eyes 
situated in the crown of the head. In the genus 
Blatta, the domestic cricket, and some other in- 
stances, these auxiliary organs are wanting, hut there 
is a subdiaphanous space over the base of the antennae 
