ii6 OHIO BIOLOGICAL vSURVRY 



EXPLANATION OF PLATE VIIL 



Some Gross Anatomy of Syrphidae. 



Fig. 151 Dorsal view of male imago(5)'r/>//«5 sp.) with the principal structural fea- 

 tures named. The following names of veins are sometimes used instead of 

 those given; 



Mediastinal for auxiliary. 



Sub-costal for ist. longitudinal. 



Radial for 2nd longitudinal. 



Cubital for 3rd longitudinal. 



Discal for 4tli longitudinal. 



Postical for 5th longitvidinal. 



Anal for 6th longitudinal. 



"Vena spuria" for false vein. 



Likewise the following names of cells may be used: 



Mediastinal for costal. 



Cubital for sub-marginal. 



Sub-apical for ist. posterior. 



2nd. posterior for discal. 



Radial for ist. or 2nd. basal. 

 Fig. 152 Dorsal view of head of Ceria tridens to show antennae with a terminal 

 style (S). 



Figures 153-157 inclusive, mouth-parts of adtilt SyrpJms americanus. 



The labium with sides spread showing the inner surface. 



The maxilla; a, maxillary palp; b, maxillary lobe. 



Hypopharynx. 



Ivabrum. 



Proboscis with parts intact. 



I^ateral view of body of Sphacrophoria cyliiidrica with most of appendages 



removed; a, prothorax with the prothoracic spiracle just above the letter; 



b, mesopleura; c, pteropleura; d, sternopleura; e, metapleura; f, hypopleura 



with the metathoracic spiracle directly above the letter. 1-6, abdominal 



segments. 

 Fig- 159 Two branched hairs; a, from Eristalis tenax; b, from Evistalis fJavipes. 

 Fig. 160 Olfactory pit from antenna as it appears in section, showing a few of the 



perceptory end-organs. 

 Fig. i6[ Outline drawing of median longitudinal section of antenna showing location 



of olfactory pit. 



