28 G 
NORTH AMERICAN GYRINUS (cOLEOPTERA) 
10. Gyrinus bifarius new si)ecies 
Moderately elongate and of average convexity; ))lack, polished, sides wiflely 
bronzed, sometimes distinctly, sometimes rather obscurely so. ^^'ith a strong 
lens the elytra are seen to be very finely alutaceoiis and numerously minutely 
l)unctulate over the entire surface, a little more noticeably so in the female, 
d'he punctures of the outer elytral striae are but little larger than those to- 
ward the suture, the eleventh stria well above the margin, nearly as distant 
therefrom as in aeneolus and woodruffi. Body beneath nearly uniformly 
rufo-testaceous or ferruginous. 
Male genitalia. Rufo-testaceous, middle lobe constricted in a peculiar 
manner at its apical third, so as to i)resent the appearance of an elongate 
superiorly flattened appendix, which is about one-thiixl as wide as the lateral 
lobes. l)roa(lly concave in a longitudinal sense, acuminate at base, and nar- 
rowly rounded at tii). 
Length, 4.2 to 6. .5 mm.; width, 2. .35 to 3.0 mm. The extremes are both 
very excei)tional, the great majority of s])ecimens lying between 5 and b mm. 
in length. 
Type locality. — Paris, Maine. Type in the aaithor’s eolh'e- 
I ion. 
Th(‘ type' is a male Ix'aring; eUitc' 8 29 17 and is oiu' ot a mis- 
(•('llaneons lot, ineluding some four or five species, taken ley 
h'rost from the Little Androscoggin River at that ]ilace. The 
following localities are rejiresented in my series — (Quebec (St. 
l)('nis — Ouillet): Alaine (Paris): New York (Ithaca; Waterville — 
Notman): Michigan (Manistirpie River, Schoolcraft Cknmty, 
and Plui-on (Mountain (dub, Lake Superior — A. W. Andrews): 
South Dakota (Rrookings): Colorado ((llenwood S])rings — Fen- 
yes): (Manitoba (Le Pas and Kettle Ra])ids — Wallis): Oregon 
(‘'()r”;Th(' Dalles — Wickham): Nevada: California (Bishop — 
F('ny('s; Lassen ('ounty — Nunenmacher; Eldorado County; 
.Mokc'hmme Hill — Blaisdi'll; Sacramento; (luerneville, Sonoma 
('ouidy- Blaisdell; Athloiu', Afi'i'ci'd (’ouidy — Alonzo Davis; 
I’njaro- Wickham; Hakersfic'ld .1. (). Mai'tin; Riv('i'sid('). 
ddiis is OIK' of om- most widi'ly dispt'rsed sjiecii'S, ranging 
from Maim' to ( 'alilbrnia, common enough in colh'ctions with- 
out doubt-, but mix('d with oiu' or another of st'vera-l sjeecies 
which it more' or less closi'ly resi'inbh's. There is no gri'at dif- 
ficulty in sejiarating it from any of its closer allies excejit con- 
Ji/ti.s, if OIK' us('s a h'lis strong ('iiough to show up the tine alu- 
taci'ous sculpture and minute iiuiu'tulat ion of the elytra, which 
