200 Journal New York Entomological Society. [VoL xxiv, 



frontal carina, which is located between the antennal pits or just a 

 little above them. The frontal carina is a protuberance of varying 

 form, bluntly ridged in some species, sharply ridged in others, and 

 even entirely absent in some cases. 



The frons extends from the vertex to the upper margin of the 

 clypeus and with a triangular prolongation on each side extending 

 downward between the clypeus and the eye to the base of the mandi- 

 ble. The area between the bases of the antennae and the central 

 part of the dorsal margin of the clypeus is called the frontal shield. 

 The logitudinal grooves extending downward on each side from the 

 base of the antennce and ending in a pit halfway down the sides of 

 the clypeus are termed frontal grooves in this paper, and the pits are 

 termed lateral foveolje. 



The clypeus is a trapezoidal, more or less flattened plate occupy- 

 ing the lower front portion of the head. It is marked off from the 

 frons by strong sutures, or sometimes by elevated ridges along its 

 upper margin. Along its lower margin it bears the labrum. This 

 margin is quite straight and transverse, its outer fourth, however, 

 turning rather sharply upward and outward toward the eye. The 

 sides of the clypeus curve downward toward the base of the eye. In 

 the male it is more regularly trapezoidal in form, while in the female 

 its inferior half is usually much wider. The smooth impunctate area 

 between the base of the mandible and the lower part of the eye is 

 probably formed by a posterior extension of the frons and an anterior 

 extension of the gena. This area may be called the malar space. 



The labrum is attached to the lower margin of the clypeus but 

 slightly behind the outer surface of this margin, and varies in form 

 in different species as well as in the sexes of the same species, some- 

 times appearing one-lobed, sometimes two-lobed, sometimes three- 

 lobed. The general form of the labrum is triangular or trapeziform 

 and it extends downward in approximately the same plane as the 

 clypeus. 



The gencE or cheeks are the sides of the head behind the eyes. 

 There is no line of demarcation between the gense and the occiput, 

 or between the genae and the vertex. They are widest along the 

 upper half, gradually narrowing toward the mandibles. 



The antennae are situated on the frons opposite the middle of the 

 eyes. The distance between their insertions is equal to that between 



