18. 

 EMPIS BOREALIS. 



Order Diptera. Fam. Empida?. 



Type of the Genus, Empis tessellata Fab. 

 Empis Linn., Fab., Meig., Curt. — Asilus Linn., Geoff. 



Antennce inserted in front of the crown, apiiroximating, porrected, 

 short and 5-jointed, 2 basal joints pilose, Istcylindric and elongated, 

 2nd subovate, 3rd the longest compressed, stout at the base and sud- 

 denly narrowed towards the apex, 4th minute cup-shaped, 5th long, 

 slender and acuminated (3). 



Labrum horny, hollow, dilated at the base, bifid at the apex {\ b). 

 Tongue horny, linear, acute, as long as the labrum (c). 

 Mandibles none. 



Maxilla very long and slender, but shorter than the labrum, acumi- 

 nated (e) . Palpi attached to the base of the maxillae but not half so 

 long, porrected, pilose and slightly clavate (/). 



Mentum bisinuate, slender and rather short (A). Lip very long and 

 clavate, being very narrow at the base, the apex bilobed and hairy {g). 

 Proboscis longest in the male, often half the length of the animal (2), vertical 

 or inflected under the breast : head small and globose: eyes contiguous in 

 the male, oval and lateral: ocelli ^placed in triangle at the back part of 

 the head. Wings ample, generally most so in the female (9); incumbent and 

 parallel in repose, loith an oblique apical nervure, and a conical cell on the 

 disc: halteres clubbed. Abdomen slender in the male slightly clavate, 

 truncated and cleft at the apex ; stout and conical in the female, terminated 

 by 2 styles; ovipositor long and slender. Legs long, especially in the 

 male and frequently ciliated in the females; tibise, posterior sometimes cla- 

 vate in the males: tarsi long and 5-jointed, basal joints frequently incras- 

 sated in the males : claws long and curved ; pulvilli bilobed {8, fore leg). 



BoHEALis Linn. Faun. Suec. No. 1.895. — Curt. Guide, Gen. 1207. 28. 

 In the Author's and other Cabinets. 



There is a very considei'able difference in the contour of this group 

 which has led to its dismemberment, yet there are such connecting 

 forms that the necessity for making genera of them may be doubtful; 

 for instance, although the wings of the female E. borealis are so re- 

 markable, in the male they are like those of the typical Empidae, and 

 even in the females they are not always angulated, as ma}^ be seen 

 by the coloured figure ; there is a great variation in the proportions 

 of the antennae in the different species, and my E. Scotica completely 

 unites the thick-thighed group with the typical genus. Empis is 

 nearly related to the Asili on one side and to Rhamphomyia (pi. 51 7) 

 on the other, and they all live by sucking other flies : the following 

 pecies have been recorded as British : 



1 



