Description of a Netv Dipterous Insect. By J. Dehtj. 183 

 Dimensions of the Head and its Parts. 



Thorax. — The scutum of the mesothorax or mesonotum for a 

 length of 0"15 mm. from its anterior apex is bluntly conical. Its 

 lateral sides are after this nearly parallel, with a very slight 

 rounded constriction in the middle. The dorsum carries on each side 

 two irregular longitudinal rows of spare stout bristles, with a few 

 scattered ones in the middle between the two internal rows. Lateral 

 appendages, or calli humerales, project from either side of the 

 anterior portion of the mesonotum just above the insertion of the 

 anterior coxse. 



The scutellum is narrow, transverse, with acute lateral angles, 

 near to each of which six to eight bristles are planted, while the 

 dorsal portion is glabrous. The metathoracic scutum is well 

 developed, transverse, and shows by transparency a dorsal transverse 

 trachea. 



Dimensions of the Mesonotum and Scutellum. 



Mikrons. 



Mesonotum .. Length 540 



.. Breadth 420 



Scutellum .. Length (antero-posterior) .. .. 90 



„ .. Breadth (transverse) 240 



Thoracic Appendages. 



A. Legs. — The legs in both sexes are long and slender in all 

 their parts, especially in the ^ , the coxae being the stoutest portion. 

 These latter carry a few stiff curved bristles near their extremities, 

 on their lower surface. The linear, middle, and hind femurs and 

 tibias are very slightly arched. The trochanters are small and 



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