214 PROCEEDINGS OF THE ACADEMY OP 



and appears in the whole organization as well as in the habits of the species. 

 Still this contrast is not equally marked in all the species of the present sec- 

 tion. Its typical representatives are the European L. annulus, quadri- 

 maculata, etc., and the American L. cinctipes, solitaria, imma- 

 tura; next come the European L. xanthoptera and the American L. 

 indigena, trioCellata; finally the European L. macrostigma, 

 tripunctata, etc., and the American L. t r i s t i g m a. In these species, 

 the striking habitual characters of the types are softened down, and the con- 

 trast with Dicranomyiais weakened. The structure of the forceps of the 

 (J 1 undergoes modification in accordance with the rest of the body. 



For this reason I consider the establishment of this section as only provi- 

 sional, not having been able for the present to effect a better subdivision. 



L. cinctipes. Thorax vittis quatuor, femora annulis duobus fuscis ; alae 

 fusco maculate et nebulosa? ; ad apicem vena? subcostalis macula ocellata ; 

 long. lin. 5-6. 



Say, Journ. Acad. Phil. iii. 21, 4. 



Wiedem. Auss. Zweifl. i. 32, 15. 



Proboscis and palpi infuscated ; antenna? fuscous, first three joints ferrugi- 

 nous ; front cinereous ; vertex with a brown spot ; its sides, as well as the 

 underside of the head, reddish yellow. Collare yellow with brown spots ; pra?- 

 scutum with four black stripes ; the intermediate ones approach the collare 

 before and reach the scutum behind ; the lateral ones are abbreviated before 

 and extend behind over the scutum, the sides of the scutellum and the meta- 

 thorax ; there are some indistinct brown spots on the humeri and the pleura? ; 

 the ground color of the thorax (that is the interval of the stripes, as well as 

 the pleura?, ) has a pale yellowish sericeous reflection ; the anterior part of the 

 intermediate stripes has a. reflection of the same color ; halteres pale, with a 

 brown ring a little below the middle of the stem, and a brown spot at the base 

 of the knob ; feet ferruginous yellow ; femora with two brown rings ; the one 

 a little beyond, the other near the tip ; tarsi infuscated. Abdomen ferruginous 

 yellow ; segments of the tergum with black stripes on their posterior margins ; 

 lateral edge of the abdomen also black ; venter yellow ; genitals of 9 ferru- 

 ginous. Wings yellowish with brown spots and clouds ; four spots near the 

 anterior margin ; the first near the basis : second, at origin of the petiole ; third, 

 double spot, at the tip of the mediastinal vein and the origin of the fork ; 

 fourth, ocellated, at the tip of the subcostal vein ; cross-veins infuscated ; a 

 pale grey band, beginning at the anterior margin, near the tip, crosses the 

 apical area?, sends a branch across the discal areolet and expands into a large 

 diluted spot in the last externo-medial area ; several diluted pale grey shades 

 in the anal, axillary and subaxillary area?, leaving some pellucid spots along 

 the posterior margin. 



Missouri (Say,) Illinois (Mr. Kennicott,) Mass. (Mr. Scudder.) 



I have but two specimens in my possession, one of which seems immature, 

 its thorax being yellowish ; the description is drawn from the other (a 9 ) 

 which is darker in its coloring and shows the peculiar sericeous reflection 

 mentioned above. 



L. i m m a t u r a. Thorax vittis quatuor, femora annulis tribus fuscis ; ala? 

 fusco-maculata? et nebulosa?, macula ad apicem vena? subcostalis integra (nee 

 ocellata) ; long. lin. 4-5. 



Very like the preceding species, but showing the following differences : it is 

 smaller in size ; the femora, besides the two brown rings beyond the middle, 

 have a third one in the middle ; it is pale, although distinct, especially on the 

 anterior pair ; the lateral edges of the abdomen are black, but there are no 

 black stripes on the posterior margins of the segments ; there is a brown spot 

 instead of an ocellus at the tip of the subcostal vein ; the grey band at the 



[Aug. 



