64 Journal New York Entomological Society. [Voi. xviii. 



the normal one of the left side. It is located in a separate fossa in 

 all respects like the normal ones, and consists of the usual three 

 joints. The joints are all slightly, but not very materially, different 

 from the normal ones in shape. The third joint lacks the dorsal 

 arista or bristle, but there is present a small tubercle in the position 

 of the arista (Fig. 5), and this I believe is the rudiment of the arista. 

 In the normal antenna of this species the upper and terminal por- 

 tions of the third joint are pigmented with black, but in the extra 

 antenna the color pattern is reversed, being dark below and yellow 

 above (cf. Figs. 5 and 6). There is no supra-antennal spot such as 

 is seen above the insertion of the normal antenna. The third antenna 

 is also somewhat smaller than the others. 



The vertical triangle is in the normal position, but is somewhat 

 misshapen owing to the absence of the compound eye on the left side, 

 which should compress it into a wedge-like form (as in Fig. 7). It 

 possesses the three ocelli of the usual size and nearly normal ar- 

 rangement (Fig. 5 v). In addition to this there is a supernumerary 

 triangle (Fig. 5, Sv), situated between the normal one and the super- 

 numerary antenna. It bears two well-developed ocelli, the posterior 

 ones a little smaller than usual, but the anterior ocellus is wanting, 

 unless a small prominence near the anterior end of the triangle is to 

 be considered its rudiment. If such is the case, it is entirely devoid 

 of a lens. The position of this triangle is abnormal in that it is out 

 of the median plane of the head and is turned at a wide angle to 

 this plane, pointing downward on the side of the head. It is situated 

 between the frons and the occiput, thus occupying a portion of the 

 space usually filled by the large compound eye. The frons and the 

 occiput do not quite meet around this triangle, and somewhat mem- 

 branous areas are left above and below it between the frontal and 

 occipital sclerites. 



The occiput is greatly distorted on the left side, as a result of the 

 absence of the eye, and it reaches forward on the side of the head 

 to meet the face. It is much wrinkled, and a deep fold runs diag- 

 onally downward and forward across it (Figs. 4 and 5). 



The gena or cheek, normally, is completely fused with the occiput, 

 while a shallow suture marks it off from the face. In this specimen 

 the facial suture is much exaggerated and the cheek is also marked 

 off above from the occiput by a deep groove. The cheek is also 

 somewhat distorted (Fig. 4, G). 



