scarcely ever recognized. The following localities are known to me. 

 Wyoming (Fort Laramie type) ; Montana (Kalispell Wickham) ; 

 New Mexico (Ft. Wingate Sherman collection) ; Nevada (a male in 

 the Sharp collection correctly referred) ; Humboldt Lake, Nevada 

 (Wickham collection) ; Owens Lake, California (G. R. Pilate). 



A. nigripalpis Sahib. Sv. Vet. Ak. Handl. 17, 4, p. 56. 

 borealis Shp. On Dytiscidae, p. 513. 

 dissimilis Sahib, i. litt. 



Form elongate, more or less obovate, especially in the female ; males shining, 

 females sometimes as shining as the males, but usually dutler, often quite opaque. 

 Head, thorax, and body beneath, black ; elytra varying from brown to fuscous, 

 with side margins more or less paler, surface commonly with a distinct aeneous 

 lustre; legs rufous, the femora darker, antennae with the outer joints apically 

 infuscate, last palpal joint almost entirely blackish. Elytra finely reticulate in 

 the male, the meshes unequal basomedially, becoming rather smaller and nearly 

 equal toward the sides and apex ; minute punctulation sparse and extremely in- 

 distinct, the punctules sometimes within the meshes, sometimes at the intersec- 

 tions. In the female the reticulation is stronger, becoming gradually somewhat 

 smoother apically. Length of metasternum between meso-coxae and coxal plates 

 one-half the length of the latter. Pro- and mesotarsi quite strongly incrassate, 

 the glandular hairs tipped with rather large oblong oval palettes. Protarsal 

 claws of male somewhat elongate, slender, not much curved, the posterior one 

 sensibly sinuate beneath. Length 6.5 to 6.8 mm. 



The identification of the present species with the Siberian nigripalpis 

 of Sahlberg is due I think to Sharp. This has been verified recently 

 for me by Mr. Arrow, who writes that our Arctic American specimens 

 are apparently identical with the type of borealis Sharp, which latter 

 Sharp has stated in his monograph (p. 924) to be in his belief the same 

 as nigripalpis. This is the species recorded under the name longulus 

 Lee. in Packard's Labrador List. 



I have seen examples from Stupart's Bay (Hudson Bay), and 

 numerous specimens taken by the Canadian Arctic Expedition along 

 the Arctic shores of British America and Alaska. In the report of 

 the Canadian Arctic Expedition (Part E, Coleoptera) Mr. Sherman 

 quotes the following localities from the material sent him for deter- 

 mination. Colville Mts., Wollaston Peninsula, Victoria Island ; 

 Bernard Harbor, N. W. T., and Demarcation Point, Barter Island, 

 Collinson Point and Teller, all in Alaska. He also gives Cape Digges, 

 Hudson Strait. 



This species is quite variable in color, and on examination I am 

 quite convinced that the two specimens from Collinson Point which 

 Mr. Sherman refers to obsoletus Lee., are only a color form of the 

 present species with yellowish brown elytra. 



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