20 PROCEEDINGS OF THE NATIONAL MUSEUM vol.69 



and Artillery horses of both armies were killed in numbers and in 

 some instances every horse and mule was killed on some planta- 

 tions. The gnats do not breed in the deep waters of the Mississippi 

 itself, and as no overflows occur now there are no longer extensive 

 breeding places, hence we have an absence of the Simuliums. 



EUSIMULIUM CONGAREENARUM, new species 



SinmUum ineridionale Malloch (part), U. S. Dept. Ag^r., Bur. Ent., tech. ser. 

 No. 26, 1914, p. 50. 



Female. — Thorax and head bluish gray with pale, sparse, closely 

 appressed and somewhat scale-like pile ; front moderately narrowed ; 

 antennae small, shorter than fore basitarsus, the two basal joints 

 brownish, remainder black; legs, including fore coxae yellowish 

 brown, apices of tibiae and tarsi darker; second hind tarsus with 

 moderate dorsal incision; basal tooth of claws rather small; fore 

 tarsi slender, the third and fourth joints a little flattened; dorsal 

 plates of abdomen broad, blackish, becoming bluish gray posteriorly ; 

 sides of second tergite with large bluish gray pollino.se patches 

 clothed with short white pile. Hypopygium as in pecuanim. (Fig. 

 45.) Wing veins brownish, more yellowish basally; stem vein white 

 pilose ; length about 3 mm. ; wing 2.75 mm. 



This species is apparently nearest to aureum. The brassy scale-like 

 pile on the thorax and postnotum of aureum serve to separate them. 



Twenty-four specimens. 



Type locality. — Congaree, S. C. 



r2/i»e.— female, paratypes 23 females. Cat. No. 28333, U.S.N.M. 



Distribution. — South Carolina: Congaree, March 17 and April 

 22, 1912 (Jennings and King). 



EUSIMULIUM DACOTENSE, new species 



The pile on the stem vein is dark as in pecuai^m. 



Female hypopygium: The tooth on the arm of the genital fork 

 is single and slighter, while the arms are less expanded or more 

 plate-like than in pecuarum with which it is otherwise identical. 

 (Fig. 48.) 



Male hypopygium: Side piece short conic with bridge and 

 reentrant piece. Clasper slender, conical, pointed at tip, with a 

 small tooth, almost as long as side-piece but much narrower. 

 Adminiculum very broad, full, convex, hirsute except toward the 

 wings, the basal prongs short, pointed and directed straight basally. 

 Adminiculum arm forming a long folded ridge with two or three 

 large stout teeth at the prominence of the ridge on each side. 

 Lateral chitinous plate large, conical. (Figs. 49, 50, and 51.) 



Type locality. — Brookings, S. Dak. 



