NORTH AMERICAN GYRINUS (cOLEOPTERA) 
292 
IS. Gyrinus maculiventris LeCoiite 
Form rather elongate, moderately convex, above black, highly polished, 
sides of elytra green bronzed, alntaceons sculpture only detectable under 
high power. Punctured striae not impressed, the outer ones a little coarser, 
the eleventh close to the margin. Body beneath black bronzed, pro- and 
epipleura and sides of ventral segments rufous. 
Mdlc (/eirilaUa. — Color dark brown to brownish testaceous; middle lobe 
with tip narrow, tip laterally compressed so as to be vertical in ])lane. 
Loijilh, ft to ().4 mm.; width, 2.5 to 5.25 mm. 
Type localUy . — Ltiko Superior. 
Known to int' from New Jersey { L:ik(‘ Hop:itconf>;) ; Afiehi- 
jj;iin (Huron Mountain Clult) : Illinois (“N. 111.”): Iowa (Elina-" - 
Wickham): Minnesota (Duluth): South Dakota (Brookings 
and Volga): Manitoba (Winnipeg; Aweme; Husaviek; St. 
Norbert; Le Pas; Mile 256, Pludson Bay Bailway; Piquitenay 
River): Alberta (Edmonton). 
A northern species of moderately large size and rather narrow 
form, at once recognizalde hy the bright rufous sides of the 
viuitral segments contrasting sharjily with the dark median 
area. The species seems to be very abundant north of Lake 
iSuperior and in Alanitoba. 
19. Gyrinus pleuralis new species 
Size hirge, form moderate, rather flatly arched in profile; black, sometimes 
slightly aeneous, highly polished, sides evidently but not very consiticuously 
green bronzed; entire surface of elytra rather thickly micro-punctidate and 
minutely alutaceous in both se.xes, the sculpture better defined toward the 
ai)(!X, tiecoming barely visible at base; strial punctures tine, a little stronger 
in t he outer rows. Truidc beneath metallic black, anal segment more or less 
rufescent apically as a rule; hypomera and epiiileura varying from clear 
rufous to rufo-piceous. 
Mdlc (jcnildlid. — Brownish jiiceous; middle lobe gradually decreasing in 
width from base to the narrowly rounded tip, the upper surface carinate in 
more than apical half. At a distance from the tip eciual to the ajiical width 
of the lateral lobes, the middle lobe is one-half as wide as the latter. 
Lodjlli, ().2 to 7 mm.; width, 5.:f to 5.75 mm. 
I'ype locality. — L;irami(‘, Wyoming. The tyi)e, in tlie author’s 
colh'ctioii, is a male collected by Prof. A\dckham. Paratyiies 
are in his colk'etiou. 
'riu' following tiddilioual localities are rejirestmti'd in tlu' 
small seri(‘s at hand, (lunuison, C'olora.do ( PfUiyi's) : Leth- 
bridg(‘, i\lb(Mta (Wallis): Washington State' (‘‘\\’. d’.”) : Tu- 
oluimu' (’ouidy, ( 'alifornia. 
