948 CHARLES PauL ALEXANDER 
42. 
43. 
46. 
47. 
48. 
Coloration bluish gray, including the abdomen; ninth tergite (Plate L, 284) with the 
caudal margin bluntly toothed. [Ross’s Voyage to the Arctic Regions, p. 77, pl. a, 
fig 15 SIS STs oie ape eer ek cae RN bie A Oe T. arctica Curt. 
Coloration brown, the abdomen dull brownish yellow with an interrupted dorsal stripe; 
ninth tergite (Plate L, 283) short and broad, the caudal margin heavily chitinized, 
deeply concave, and slightly roughened in places, the lateral angles produced into 
conspicuous chitinized points. [Berl. Ent. Ztschr., vol. 7, p. 278. 1863.] (Plate LIV, 
338, lateral aspect of male hypopygium.).................... T. septentrionalis Loew 
Ninth tergite (Plate L, 280) small, heavily chitinized, shiny black, the caudal margin 
with a deep U-shaped notch, a second tooth on either side, subbasal in position; wing 
of male 17.5 mm.; head light gray, with a narrow, impressed median line; antennae 
with the first three flagellar segments indistinctly bicolorous, the remainder uniformly 
dark brown; abdomen orange, with an interrupted dorso-median stripe. [Berl. Ent. 
Ztschr., vol. 8, p. 60. 1864.] (Plate LIV, 339, lateral aspect of male hypopygium.) 
T. centralis Loew 
Ninth: tergite larger, not as/above:..5.%.. 6.55 <2 3860s ose ee eee 44 
. Ninth tergite (Plate L, 279) heavily chitinized, black, hollowed out in a shallow saucer, 
the dorsal surface near the caudal margin with a prominent median tooth that is 
directed backward; margin of the saucer denticulate, more strongly behind; wing 
16.8 mm.; head light gray; thorax dull gray, the prescutal .stripes margined with 
brown. [Berl. Ent. Ztschr., vol. 7, p. 284. 1863.] (Plate XLVI, 227, wing; Plate 
LIV, 387, lateral aspect of male hypopygium.)................... T. balioptera Loew 
Ninth tergite not’ as above: =: .0..5..0. 9.5. .ce0 dss sok eee eee ee 45 
. Ninth tergite (Plate L, 282) very large and extensive, narrowed slightly toward the 
apex, which consists of a flattened yellowish margin bearing a deep tho small median 
notch, the broad adjacent lobes with about three tiny teeth, the outermost one the 
largest; the part of the tergite behind the yellow caudal margin elevated, black, and 
including the basal two-thirds of the segment; wing 15 mm.; antennae blackish; 
prescutum light grayish brown, with about five dark brown stripes; abdominal seg- 
ments dark brownish black, the caudal margin of each segment bright yellow, the 
lateral margins broadly gray; wings with a heavy pattern; a conspicuous dark spot 
at the base of the wing. [Berl. Ent. Ztschr., vol. 8, p. 57. 1864.]....7. ternaria Loew 
Ninth: tergite not as above...:.. 5.5.6. o20b. oe eu een cet i eee 46 
Ninth tergite (Plate L, 281) telescoped beneath segments 7 and 8; the sclerite not 
chitinized, very broad and short, the caudal margin broadly concave and provided 
with a uniform fringe of long yellow hairs; wing 15.7 mm.; antennae somewhat 
bicolorous, the basal enlargement of the flagellar segments dark brown, the remainder 
of each segment a little paler; prescutum whitish gray, with broad dull gray stripes 
narrowly and indistinctly margined with brown; abdomen dull yellow, with an indistinct 
dorso-meuian stripe which broadens out on segments 6 to 8; less distinct submarginal 
stripes on the sides of the abdomen. [Berl. Ent. Ztschr., vol. 8, p. 59. 1864.] (Plate 
LIV, 341, lateral aspect of male hypopygium.)................. T. canadensis Loew 
Ninth ‘tergite not’ as jabovel,. ¢.52 56.5.) 6cs cs. ee ceo ae ee ee 47 
Ninth tergite (Plate L, 276) large, pale, not chitinized, with two rounded lobes separated 
by a narrow, deep notch; antennae elongate, the segments of the flagellum not incised 
beneath; ventro-caudal angle of each pleurite bearing a prominent, pale, fleshy lobe. 
[Berl. Ent. Ztschr., vol. 7, p. 286. 1863.] (Plate XLV, 212, wing.) 
T. angustipennis Loew 
Ninth tergite not as above, more or less chitinized caudally; antennae shorter, the flagellar 
segments deeply incised ‘beneath. <2: \.. 22.2... 0: ses eee 48 
Ninth tergite (Plate L, 277) with a broad median chitinized tooth on the caudal margin; 
adjacent lateral lobes terminating in small, acute, chitinized points; antennae moderate 
in length, extending slightly beyond the wing root; prescutum fawn-colored, with 
four broad grayish brown stripes narrowly margined with brown; abdomen dull yellow 
with a rather indistinct brownish median stripe which is clearer behind. -[Berl. Ent. 
Ztschr., volo wk p: 283. W863i] 20 2 oe eens T. serta Loew 
