EXTERNAL ANATOMY 53 



the eyes and antennfe to about the middle of the frontal 

 area, where it enlarges again, and ends below in a prom- 

 inent, straight, transverse suture. Faint lines indicate that 

 the epicranium is formed by the fusion of two originally 

 separate pieces. An obscure ridge between the upper ends 

 of the eyes perhaps also indicates the union of two segments. 

 The large projecting compound eyes (e), are oval and highly 

 polished and are situated on the upper portion of the sides of 

 the head. These eyes are composed of many thousands of 

 hexagonal facets or lenses andaremarked with parallel verti- 

 cal bands of brown pigment. A little in front of the upper 

 margin of each of the compound eyes is a convex oval area, 

 in which the integument is so thin and transparent that the 

 tissue below can be seen. These minute spots are the ocelli 

 {oc) or simple ej^es. A third ocellus can be seen between the 

 antenna on the median line of the epicranium. The antennae 

 {ant) are composed of a larger basal joint and twenty-six 

 movable rings which increase gradually in length from base 

 to tip. Thebasal joints ofthe antennae are fastened to the cen- 

 ters of two oval areas, the antennary fossae {ant. /bs), which 

 are located between the eyes on the narrow frontal portion of 

 the epicranium. The antenna can be moved in all directions. 

 The lower and straight edge of the epicranium articulates 

 with a wide, short plate, the clypeus {cly), the sides of which 

 are deeply notched, showing the traces of a division into two 

 plates. In front of this is a movable, flap-like labrum (Ibr), 

 the free edge of which is deeply notched on the median line, 

 the remnant ofthe suture formed by the union of the halves 

 or paired appendages which the labrum represents. On the 

 sideof the head is a suture, which runs from the lower anterior 

 angle ofthe eye to the lower margin of the epicranium, and 

 separates the latter from the large plate, the gena (gena), 

 which forms the side of the head, and terminates below in 

 a free, pointed edge. Between the low^er anterior edge ofthe 

 gena and the clypeus is a dark colored area, the outer sur- 

 face ofthe basal portion of the mandible (md). 



