EXTERNAL ANATOMY OF INSECTS. 485 



the front is often elevated between those organs. In 

 Ponera, one tribe of them, this elevation is bilobed, 

 and receives between its lobes the vertex of the post- 

 nasus. In the hornet ( Vespa Crabro) the elevation is a 

 triangle, with its vertex towards the mouth. In Sagra 

 it is marked out into three triangles, the postnasus mak- 

 ing a fourth, with the vertexes meeting in the centre. 

 In the Dynastidce and Scarabdcid.ee the horns are often 

 frontal appendages,- as is that of Empusa Latr., a leaf- 

 insect, and probably those of Sphinx latropkdeF., which 

 affords a singular instance of a horned Lepidopterous one. 

 Sometimes it is an ample space, reducing the nose to a 

 very narrow line, as in the Stapkylinida, or sending 

 forth a lobe on each side, as before mentioned, which 

 embraces the nose. In a species of bug from Brazil, re- 

 lated to Aradus F., these lobes are dilated, foliaceous, 

 and meet before the nose, so as to form a remarkable 

 extended frontlet to the head. In others this part is ex- 

 tremely minute : thus in many male flies and other in- 

 sects, as the Libellulina, where the eyes touch each other, 

 the front is cut off from the vertex and reduced to a small 

 angle. In the female flies the communication with the ver- 

 tex is kept open, and the front consequently longer. In 

 the horse-flies ( Tabanidde), in Hcematopota, and Hepta- 

 toma, the frontal space is wider than in the rest of that 

 tribe. Many of these are distinguished by a levigated 

 area behind the antennae in the part we are treating of. 

 In the Libellulina, and in the drone-bee, whose eyes are 

 confluent, the stemmata are in the front. In many Or- 

 thoptera also, as Locusta Leach, one of them is below 

 the antenna? ; and in the lanthorn-fly tribe (Fulgoridce), 

 both these organs, which are situate between them and 



