ir. C. FALL 
295 
Hudson Bay Railroad— Wallis) : Alberta (Edinonlon— (’arr) : 
Moiitana (Alissoula— A. B. Wolcott): Washington (Olympia— 
Kincaid). 
22. Gyrinus parcus Say 
Form strongly convex, nearly symmetrically arched in i)rofile; black, sides 
distinctly and rather broadly bronzed, surface in the male i)olished ami not 
visibly alutaceous, in the female very finely alutaceous and moderately shin- 
ing, the micro-sculi)ture more evident toward the sides and apex; st rial punc- 
tures rather coarse, especially toward the sides, where the rows an' visibly 
impressed; eleventh stria strictly marginal throughout. Body beneatli 
metallic black, anal segment not or onlv feebly rufescent, legs rufous. 
Male genilalia. Dark rufous or rufo-piceous, middle lobe obtu.sely carin- 
ate, one-half as wide apically as the lateral lobes, the tip rounded. 
Length, 4.25 to 5.3 nun.; width, 2.4 to 2.8 mm. 
Type locality. — (Mexico. 
Known to me from Western Pennsylvania (Jeannette — 
Klages): Kansas (Onaga; Douglas C'ounty; “Kansas Willis- 
ton”- — Snow): Texas (San Antonio; Brownsville; Davis Aloun- 
tains) : C'alifornia (San Diego — Blaisdell). It also occurs 
through (Mexico and Guatemala to Peru ;ind Glide — a most 
('xtraordinary range in latitude. 
The rather small size, v('ry convex form, coarse sti'ial punc- 
ture's with slightly canaliculate lateral rows, ai'e the sujx'rficial 
(‘haracte'rs usually redieul upon to distinguish this S])('cies. To 
these' it shoidd be' adek'd that the' eleventh sti'ia is so truly mar- 
ginal throughout as to be scarcely visible when the' inse'e*t is 
viewed in the plane of the reflexed margin. This conelition does 
not obtain so perfectly in any of our othei’ species. In borealis 
and pugionis only, are the lateral striae of the elytra as distine'tly 
imiiresseel, and both these species are mate'iially larger and 
practically outside the range of parcus see far as we now know. 
23. Gyrinus borealis Aube 
Form rather stout and convex; black, sides bronzc'd; modcratc'ly shining, 
elytra very minutely alutaceous throughout, a little more disfiticfly so in 
the female, minute punctulation nearly wanting; strial punctilio's closi' set, 
obviously larger at sides, where the .striae are very distinctly impri'ssi'd. 
Beneath black, last segment commonb^ lirown, at least in part; h'gs cli'ar 
rufous. 
Afale genilalia . — Brownish yellow, middh' lobi' strongly narrowing, supi'i- 
iorly tlattened in basal third, carimte in middle third, sti'iider and subeylin- 
drical in about the apical third, wiiieh is about oni'-tourth as wide' as I In' 
lateral lobes. 
Length, 5.5 to G.2 mm.; width, 3 to 3.(» mm. 
TRANS. -A.M. ENT. SOC., XLA II. 
