1878.] 439 [Uhler. 



black streaks on the disks and margins of the segments. The whole 

 breast, venter, and two spots on the pleura lead color, with a seri- 

 ceous gloss. 



The winged form has the pronotum blackish brown, densely pubes- 

 cent, the middle of the anterior lobe broadly depressed, covered by 

 an orange spot, lacking the bluish stripe. Coxa? yellow beneath, legs 

 brownish black, the anterior pair yellow at base, and on the under 

 side the yellow is a little farther extended. Sternum blackish, each 

 side of it yellowish. Hemelytra dark brown, with a faint paler streak 

 on the medial suture, the base and costal margin pubescent. Venter 

 cinereous, the disk of the penultimate and base of the last segment 

 yellow. 



Length to tip of hemelytra, 5 millims. Extreme width of mesotho- 

 rax, 2 millims. Unwinged, length 3-4 millims. Width of mesothorax, 

 lf-2^ millims. 



No. 29, Harris' Collection. " Water, July 20, 1827; May 15, 

 1826, and Maine, Randall, April, May. 245 & 246." 



The label is marked " larva," as if taking it to be the larva of Lim- 

 notrechus marginatus Say. The unwinged form is very common in 

 summer, on the surface of the Charles River, Mass., near Waltham. 

 At that place I saw numbers of solitary individuals skimming the 

 surface at a considerable distance from the shore. In Maryland it 

 usually congregates in groups of a score or more on the surface of 

 still pools near the banks of streams. It is quite common in North 

 and South Carolina, but no winged specimens have yet occurred to 

 me from either of those States. In Haiti, on the Grand Anse River, 

 the winged form abounds, usually in company with the unwinged. 

 Within a period of twelve years, this species first made its appearance 

 on Gwynn's Run, near Baltimore ; a few years earlier it was not to 

 be found on that stream. 



NAUCORID^E. 



Naucoris Geoff. 

 N. Poeyi. 



Naucoris Poeyi Guerin (non Amyot), Icon, du Regn. Animal, 353, 

 pi. 57, fig. 5. 



Five specimens are in the collection, labelled "Florida, Doubleday," 

 and without a number attached. They differ in no respect from spec- 

 imens collected in Cuba, Maryland, Illinois, and Massachusetts. 



