Mar., 1913.] Life-Histories of Syrphidae V. 91 



Fig. 85. End view of posterior respiratory organ, x 50; lettering as in 



Fig. 84. 

 Fig. 86. Dorsal view of puparium x 3; a, posterior respiratory appendage. 

 Fig. 87. Lateral view of puparium x 3. 

 Fig. 88. Scutellum and abdomen of female from above, showing color 



pattern, x 5. 

 Fig. 89. Wing of male, x 7. 



Figures 149, 150 Eristalis aeneas (Fab.) 

 Fig. 149. Wing of male x 7. 

 Fig. 150. Dorsal view of head and thorax of female showing characteristic 



spotting of the eyes, and poUinose thoracic pattern, x 5. 

 Fig. 17. Didea fasciata fuscipes; characteristic sculpturing on chorion of 



egg- 



EXPLANATION OF PLATE V. 



Figures 142-144, inclusive, Eristalis tenax (Linne) all the others 

 of Eristalis aeneas (Fabricious). See also Figs. 149, 150 



Fig. 131. Dorsal view of mature larva x 9; a, antenna; h, anterior larval 



respiratory cornua; c, the large tracheal trunks; d, the posterior 



respiratory tube or "rat-tail." To avoid a confusion of detail 



the vestiture is not represented in this figure. 



Fig. 132. The anterior larval respiratory cornua, much enlarged, dissected 



out to show the large trachea leading from it. 

 Fig. 133. Distal end of respiratory tube highly magnified, showing wrink- 

 ling on outside, the two inner tracheae (a), the spiracles at the 

 tip {b) and the delicate, feather-like appendages (c). 

 Fig. 134. A small area of the basal segment of the tube much enlarged, 



showing the character of the vestiture and wrinkling. 

 Fig. 135. A small area of the median segment of the tube much enlarged, 



to show the character of the vestiture and wrinkling. 

 Fig. 136. a, one of the bifid, segmental hairs of the larva, and b, one of the 

 integumental hairs of the body drawn to the same scale as 

 Figs. 134 and 135. 

 Fig. 137. The anal opening of the larva (a) with the retractile fiabellae 

 (b), much enlarged. 

 Ventral view of the head of the larva much enlarged; a, antenna; 



b, mouth hood; c, the first pair of pro-legs. 

 Ventro-lateral view of hood and oesophageal framework dis- 

 sected out, much enlarged. 

 The chitinized mouth-parts internal to the hood from the side; 

 a, booklets, possibly homologous with those of aphidiphagous 

 larvae; b, mandible-like structures; much enlarged. 

 The same as Fig. 140, ventral view. 



Eggs of E. tenax, x 17, showing method of ranking in oviposition. 

 Sculpturing of chorion of egg of E. tenax, highly magnified. 

 Larva of E. tenax a few hours after hatching; a, antenna; b, one 

 of the prolegs; c, tracheal trunks; d, posterior respiratory 

 appendage, x 17. 

 Puparium of E. aeneas from the side, x 4; a, anterior larval 

 respiratory cornua; b, pupal respiratory cornua; c, posterior 

 respiratory appendage; d, anal fiabellae; e, pro-legs. 

 Nymph, or developing imago, dissected out of puparium to 

 show connection of tracheae from pupal respiratory cornua to 

 prothorax (a); b, knee of front leg; c, wing-pads; d, scutellum; x3. 

 Pupal respiratory cornua very much enlarged showing arrange- 

 ment of spiracular papillae. 

 Two of the papillae of the pupal respiratory cornua showing 

 radiating structures believed to be the spiracles. 



