160 



C. G. LAMB. 



face is but slightly arched from eye-margin to eye-margin. The antennal joints 

 are wholly pale yellow. The arista (fig. 3) has four upper rays, a terminal ray and 

 one apical lower ray, but none on the basal part ; under a power of 90 diameters 

 one can just see a few of the usual inner row of tiny rays. The arista is bright yellow 

 up to just beyond the insertion of the second upper ray ; the rest, together with all 

 the rays, is black. The mouth vibrissae are single and very strong, and the stout 

 bristles on the jowls (lower and hind) are quite strikingly developed. The buccal 

 opening is somewhat unusual in structure. In the normal Drosophilid mouth, if 

 one looks straight into it from below, one will see the fulcrum in the form of an elongate 

 arch widely separated from the actual mouth- edges by the membranous sides which 

 join it to the same. In the present species the fulcrum follows closely and exactly 

 the mouth-margin, so that its long axis is across the mouth, instead of axial, and 

 in fact there appears to be no room for the membranous connections, and hence 



Fig. 3. Lateral and front views of head of D. paradoxa. 



little possibility for the usual mobility of the proboscis. The tongue and palpi are 

 inserted deeply in the buccal cavity ; they are both entirely pale orange. The 

 palpi are slightly clubbed at the tip and bear there a small black terminal bristle, 

 and there is a single similar bristle on the lower side of the end. 



The thoracic dorsum (fig. 2) is also pale, rather shiny yellow, although in certain 

 illuminations two indistinct orange lines can be seen showing through the chitin. 

 The surface is entirely covered with regular rows of tiny bristles, which, as usual, show 

 black against the dorsum but golden on side view ; the middle six rows of these 

 bristles (shown as four only in the figure) form the acrostichal rows. Three pairs of 

 post-sutural dorso-centrals are present, the first very small, the next long, and the last 

 very long, extending over the scutellum. There are 4 small prescutellars, and the 

 rest is as shown in the figure. The scutellum is absolutely smooth and of the same 

 yellow colour as the dorsum, as is also the metanotum. The pleura is also all of the 

 same colour ; the large terminal humeral bristle is accompanied by an almost equally 

 large one on the lower side of the humerus and 2 or 3 smaller ones. There are two 

 sternopleural bristles inserted rather closely together, the hind one being very long 

 and stout, the other about half its size. 



The legs are likewise entirely pale yellow and are well clothed with tiny bristles ; 

 the coxae carry long irregular bristles, and the front femur is provided with a lower 

 row of 6 or 7 stout bristles ; there are no special adornments on the front legs. 



