SYRPHIDAE OF MAINE. 161 



As seen from the side the anterior face is a little less than perpendicu- 

 lar rounding dorso-caudad to reach the greatest height about the anterior 

 third. The dorsal line continues convex to a little beyond mid-length 

 whence it is usually more or less concave to the tip. The ventral line is 

 gently concave in the anterior two-thirds, thence straight or convex. As 

 seen from in front, the outline is considerably flattened on the ventral side. 



Color and pattern at first similar to that of the larva but soon loosing 

 the warm tan or vinaceous and becoming a colder, dull clay color. The 

 pupal envelope becomes marked with six or seven prominent transverse 

 blackish bands not reaching the side margins, expanding a little on the 

 middle line and irregularly prolonged backwards, hooklike, at their outer 

 ends. The anterior ones are broader, the posterior ones narrower, with- 

 out the lateral expansions, and stopping much short of the lateral margins. 



Adult (Fig. 12, K). The specimens so far reared from these 

 larvae are all females. Of the described species they fit most 

 nearly the Xantho gramma divisa 1 , of Williston though in some 

 respects they agree rather better with X. felix O. S. If these 

 should prove synonymous, as Williston thought possible, the 

 species would take the older name -felix. 



I quote Williston's description with emendations to apply 

 to the specimens reared : 



"?. Length 9 to llmm. Face and cheeks yellow or reddish yellow" 

 with an opalescent reflection. "Face nearly perpendicular, gently concave 

 below the antennae, and with a large obtuse tubercle below," from which 

 the face retreats, being not at all produced again to the upper mouth edge. 

 Labellae yellow. "Front above metallic greenish black, continued as a 

 broad stripe to the base of the antennae," (the stripe occupies only about 

 one-third the width of the front) "somewhat expanded below ; on the sides 

 yellow. Antennae black ; somewhat reddish below on the sides of the sec- 

 ond, and of the third joint near the base." The yellow is more extensive 

 in my specimens, occupying much of the first and second joints and a large 

 area on the under side of the third. "Dorsum of thorax deep metallic 

 green with rather ill-defined yellow lateral stripes. Pleurae with a large 

 ill-defined spot. Scutellum a somewhat translucent yellow, its base" very 

 "narrowly black." 



Abdomen opaque black ; first segment broadly yellow on the sides en- 

 croaching minutely on the anterior corners of the second segment. 



"Second segment with an oval spot on each side," two-and-a-half to 

 three times as long as broad, the outer end cut off parallel with and "not 

 reaching the lateral margin, somewhat attenuated toward the inner end." 

 The spots separated by two-thirds their maximum width, or about y$ mm. 

 "Third and fourth segments with large rectangular spots" a little longer 

 than those on the second segment and the posterior lateral and median 

 corners both somewhat rounded off, these spots separated by a third to a 



'Proc. Am. Phil. Soc., XX, 311. 



