246 NOTES. 



breadth: hind margin of the fourth segment margined with yellow. 

 Venter black, segments 2, 3, 4, each, with a broad yellow cross-band 

 at the base, coarctate in the middle. Legs yellow; proximal half of the 

 four anterior femora black; hind femora black, except at tip; hind tibiae 

 with a brown ring in the middle, sometimes expanding over the whole 

 tibia; tarsi more or less brown. Wings with a distinct grayish tinge, 

 stigma brownish; the third vein forms a distinct sinus, encroaching upon 

 the first posterior cell. 



Male. The white spots on the pleurae are less perceptible; the 

 cross -bands are sometimes interrupted in the middle, especially in the 

 smaller specimens. In one of the specimens the spots on the second 

 segment, as well as the interrupted cross-bands are separated from the 

 lateral margin by a distinct black interval. 



Habitat, Lake Superior collect. A. Agassiz); Norway, Me. (S. I. 

 Smith); Mt. Washington, Alpine region (G. Dimmock). The largest lot 

 I received from Mr. H. K. Morrison, who collected it in the White 

 Mountains. Altogether I had fourteen males and an equal number of 

 females. 



The cross -bands and spots on the abdomen usually are greenish, 

 like those of the European I), alntti ; sometimes, however, they are 

 yellow. 



D. laxa differs from D. fuscipes Loew in the shape of the abdom- 

 inal cross-bands, which in the latter, become broader on each side, but 

 do not reach the margin; also in the color of the femora, etc. 



213. Sphaerophoria. I restore this name, however incorrect its 

 termination may be, as Melithreptus was used long before 1840 for a 

 genus of birds. 



214. Allograpta. ,,Scaeva obliqua Say, cannot well be placed in 

 any of the existing genera of this group. It does not possess the cha- 

 racteristic marks of Mesoyrapta (peculiar shape of the ocellar triangle 

 in the male, and peculiar coloring of the thorax ; it has not the large 

 development of the hypopygium of the male of SphaeropJioria ; it might 

 be placed among the species of Si/rpJnis with a linear abdomen. But, 

 in the first place, these species will, sooner or later, have to be sepa- 

 rated from the bulk of the genus ; and, in the next place, Scana obh'ijim 

 possesses in the structure of the eyes of the male, and in the peculiar 

 markings of its abdomen , sufficient characters of its own. The eyes of 

 the male are divided in two parts by a well defined line, above which 

 the facets are larger than below; the line lies a little lower than the 

 antennae and thus divides the eye in two unequal parts, the upper one 

 of which is a little larger: its coloring, in life, is more red, the lower 

 half is more purplish. This character, very striking in life, is also 

 visible in dried specimens. I have not observed it in the species of 

 Si/rphtift, or of Spliaerophoria, or of Mesograpta, which I examined alive. 

 The name Allograpta is given in allusion to the peculiar coloration of 

 the typical species. Scacca eniaryiitata Say, which I do not possess, is 

 provisionally placed in the same genus. 1 suspect that r ,,;: than one 



t.s from Mexico and the West Indies belongs to the same group; 



