122 



NORTH AMERICAN DIPTERA 



13. Eyes joined above the antennas by a narrow bridge; anterior crossvein 



long, appearing like the base of the third vein, the latter short and 



transverse, resembling a crossvein See Sciaridac 



Eyes not joined by a narrow band above the antennae; base of third 

 vein and the anterior crossvein in most cases oblique 14 



14. Prothorax without long bristles, antennae inserted above the middle of 



the head, occiput flat or concave, venation defective (Manotinae) (1). 



Manota Williston 

 Prothorax with long bristles, occiput convex, antennae inserted at or 

 belov/ the middle of the head 15 



15. Microtrichia of wings irregularly arranged or absent; auxiliary vein 



usually long; lateral ocelli in most cases far from margin of com- 

 pound eyes (Sciophilinae Edwards r= Sciophilinae Johannsen + Series 



I of Mycetophilinae Johannsen 1911 ) 16 



Microtrichia in more or less definite longitudinal lines; auxiliary vein 

 usually short; lateral ocelli touching compound eyes (Mycetophilinae 

 Edwards, Mycetophilinae Johannsen 1911, Series II) 44 



MycetophilidEe I.— 1, Manota defecta; 2, 3. Lygistorrhina singularis ; 4, Macrocera con- 

 cinna; 5. Ceroplatus longiinana; 6, 7, 8, Sciara (Sciarida;) ; 9, Platyura ignobilis ; 10. Sciophila 

 diluta; 11, Neoempheria maculipennis ; 12, Phthinia fraudulenta; 13, Leia nitens ; 14, Symmerus; 

 15, Mvcetophila insipiens ; 16, Tetragoneura sylvatica; 17, Dynatosoma fuscicornis. 



