1909] New Fossil Insects from Florissant, Colorado 253 



tion; a character very distinctive of the Odynerines; in the Vespines 

 they form a strong angle, and the anal is usually continued to the 

 margin. 



Habitat. — Miocene shales of Florissant, Colorado, 1909 {Terry 

 JDuce). A fine species, easily knowti from the Odyneri previously 

 described from Florissant by its large size. 



Messrs. Duce and Rusk obtained a single anterior wing, well 

 preserved, of Megachile prcedicta Ckll. Can. Ent. 1908, p. 31. 

 This shows that the wing is hyaline, faintly reddish, with the 

 nervures and stigma pale ferruginous. 



DiPTERA. 



Syrphus aphidopsidis n. sp. (Syrphidse.) 



9 (apparently); length 14^ mm., but owing to pressure, the 

 pointed apex of the abdomen, usually retracted in cabinet specimens, 

 is extended, giving the insect a rather peculiar appearance, and adding 

 to the length. Width of head about 3 mm., of thorax 3j, of abdomen 

 'about 4, length of wings 9. Eyes bare, about 900 fi apart on vertex, 

 the facets of uniform size, about 34 // diameter; antennas normal, the 

 apical joint large and rounded, with the usual stout bristle; thorax 

 above coal-black, without light markings; abdomen with very broad 

 light bands on the first three segments, but all interrupted in the middle 

 to the extent of about a third of a mm. ; on the first segment the base 

 is dark, but the rest light except a large median inversely cup-shaped 

 area about 2| mm. in diameter, its rim resting on the hind margin, 

 its other end connected by a stem with the dark basal area; second 

 segment with a broad basal band, interrupted in the middle, straight 

 behind, except at extreme sides where it is produced posteriorly; 

 third segment with the pale areas widening from the interruption, so 

 that they are triangular in form ; fourth segment with a fine continuous 

 pale line at base, widening laterally; wings faintly dusky; hind femora 

 stout, about 680 // diameter, their tibiae very slender. 



Venation compared with that of Syrphus arcuatus, Eupeodes 

 volucris and Sccsva pyrastri; measurements in microns: 



(1) First vein normal; after reaching the margin it really con- 

 tinues, as in the living forms, to the end of the second, so that the 

 marginal cell, while apparently open, is in reality closed. 



(2) Second vein arched, and at its tip deflected upwards; this 

 agrees much better with Syrphtis than with Eupeodes or Scceva. 



(3) Third vein beyond the anterior crOss-vein straight, with a 

 just observable arching; this is cjuite different from Scceva; also differ- 

 ent from 5. arcuatus and Eupeodes, in that what arching there is 

 begins at the cross- vein, instead of being confined to the distal part. 



(4) Spurious vein very distinct, bisecting the cross-vein a little 

 higher up than in Scceva. 



(5) Anterior cross-vein not at all oblique (more or less oblique 

 in the living species), placed about 1020 from the base of the discal 

 cell, and of course much before the middle. 



