SYRPHIDAE OF MAINE. 165 



parium is widest about 2 mm. caudad of the anterior extremity, or in the 

 region of the fifth and sixth larval segments which are of about equal 

 width in the puparium. Anterior to this point the outline from above is 

 unevenly rounded. Cephalad of the fifth segment the puparium narrows 

 noticeably to a width of 2.25 mm. in half that length and in front of this 

 constriction the outline is semicircular. Caudad of the sixth segment, or 

 widest point, is a similar constriction to a width of about 2.25 mm. at the 

 beginning of the eight larval segment. From this point the body is more 

 regularly attenuated; and the puparium, inflated a little at each segment, 

 narrows to a width of 1.25 to 1.75 mm. at about half a millimeter from 

 the posterior end. Thence it is rapidly attenuated to the respiratory or- 

 gan, if this is terminal, or is more nearly truncate if the respiratory organ 

 is directed dorsad. As seen from the side the ventral line beginning with 

 the region of the larval mouthparts is at first gently convex downward, 

 then more or less strongly concave to a point well caudad of the middle, 

 thence again convex to the posterior end. The dorsal line is strongly and 

 evenly convex dorsad and caudad to about the region of the seventh lar- 

 val segment, about three millimeters caudad of the anterior end. It is then 

 abruptly depressed or concave throughout segments seven to nine and fin- 

 ally gently convex to the posterior end. The shape as seen from in front 

 is a short oval with the long axis transversely and spherical angles at the 

 sides. The posterior half of the body retains the shape of the larva to an 

 unusual degree and is sub-triangular except that in some specimens the 

 lateral margins show moderate dorsal carinae. 



The predominating color of the puparium is maroon to black, exten- 

 sively mottled with patches of white and of pinkish brown. The dark mid- 

 dorsal line of the larva is evident over the posterior half of the puparium, 

 and is bordered with more or less extensive irregular masses of the white 

 adipose tissue of the larva. In the region of larval segment six is usually 

 a large dark area, while in front of this the color is quite dark, overlaid 

 with irregular areas of lighter color. The posterior end of the puparium, 

 including the base of the respiratory organ is almost black, the distal end 

 of the latter brown. 



Syrphus oronoensis n. sp. 



Adult (Fig. 10, C). $. A small species, the abdomen with 

 nearly parallel sides, the three principle segments opaque black 

 and each with a pair of yellow sub-triangular spots, the first pair 

 small and far apart, the others larger and more approximate. 



Length about 8 or 9 mm. Head large , broader than the thorax 

 or abdomen. Eyes bare. Frontal triangle somewhat swollen, bronze black, 

 shining, with rather long black pile which continues somewhat thickly 

 down the sides of the face to the mouth edge. Vertical triangle with long 

 black pile. Face below the antennae at first convex then very slightly con- 

 cave to the tubercle which is not prominent ; mouth edge retreating, cheeks 

 convex below. Face opalescent yellow, thinly whitish pollinose on the 



