1862.] 127 



smooth (without any teeth or projectious) on their whole length ; with a 

 longitudinal groove, running from the basis to the tip on their upper side ; 

 their roots far distant from each other, being inserted on the sides of the 

 head ; when in repose, these organs overlap each other on a considerable 

 portion of their length, the left one being the uppermost in my specimens. 



Maxillse: no distinct cardinal piece; basal piece elongated, closely ap- 

 plied to the mentum and soldered to it on its lower portion ; besides the 

 palpus, each of them bears two palpiform appendages ; one is close by the 

 palpus, inside of it, and is better seen from above than from below the 

 head; it does not reach beyond the tip of the first joint of the palpus and 

 is apparently 2-jointed, the first joint being short and annuliform, the sec- 

 ond cylindrical, stout, obtuse ; at its tip there is a very minute tubercle, 

 as if a rudimentary joint, on the inside, and a long bristle on the outside; 

 the second appendage is inserted much deeper, inside of the maxilla ; it 

 is closely applied to the mentum and can be perceived only, when this or- 

 gan is slightly removed from its usual position ; it is very small, cylindri- 

 cal and more slender than the first appendage, and consists of a single 

 joint, inserted on a tubercle. 



The palpi are rather long and stout, being but little shorter than the 

 antennae; they are 4-jointed, the two basal and the last joints being broad- 

 er than long ; the third is a little longer. 



Mentum elongated, somewhat narrowed anteriorly, bearing a trapezoidal 

 palpigerous piece, which is narrowed at the base and has a small rounded 

 projection on the inside, in the middle, especially distinct when seen from 

 above ; a bristle on each side of this projection and several bristles on the 

 outside of the palpigerous piece, between the palpi ; labial palpi consist- 

 ing of two cylindrical, short joints; the second truncated at the tip. 



The maxillfB and the palpigerous piece, with their palpi project consid- 

 erably beyond the mandibles. The basal pieces of the mandibles and the 

 mentum occupy the whole breadth of the underside of the head, their 

 basis only being enclosed in the usual excision of the lower cephalic plate. 



Prothorax trapezoidal ; slightly broader than the head anteriorly ; al- 

 most twice as broad posteriorly; its upper disc being recurved on both 

 sides, somewhat encroaches on the underside, where it is limited by a 

 sharply defined edge. On the underside, a V-shaped groove separates a 

 triangular piece covering the basal portion of the head (see fig. 86). 

 ' The two following segments of the thorax are of about the same length, 

 a little longer than the first ; they are also trapezoidal, but less narrowed 

 anteriorly; their upper disc is also recurved on both sides, so as to encroach 

 on the ventral segments. 



