112 NORTH AMERICAN TIPULIDAE 



58. Antemiae thirteen-jointed 59 



Antennae with more than tliirteen joints in both sexes. . . polymera Loew 



59. Lateral stripe and posterior margin of abdominal segments, black. 



approximata spec. n. 

 Abdomen with lateral and ventral rows of black spots 60 



60. Segments of antennal flagellum excised beneath; abdomen with dorsal 



row of spots; eighth sternite with deep, u-shaped emargination. 



brevicornis Doane 



Segments of flagellum cylindroidal ; abdomen with dorsal vitta; eighth 



sternite protuberant, scarcely emarginate stigmatica spec. n. 



Pachyrhina oslari .spec. n. (PI. IV, fig. 1., pi. V, fig. 21.) 



Tipuloid; cntirelj- black wth a graj-ish-white pruinosity. Flagellar joints 

 of the antennae prolonged beneath at the apex, giving the antennae a serrate 

 appearance. Stigma pale brown. 



Male. Length, 11.5 mm.; wing, 12.5 mm. 



Head. Face, space about base of antennae, antero-inferior periorbital mar- 

 gin and sides of occiput, densely wliite pruinose, median space of occiput dull 

 black. Proboscis verj^ short and thick, frontal prolongation beset with black 

 hairs. Antennae robust, short, entirely black, without whorls of setaceous 

 hairs, with a very short, white pubescence on the apical margin of the seg- 

 ments, the apices of segments three to seven extended beneath, less marked in 

 the following segments, joints eleven and twelve longer than the preceding 

 ones, the last joint very slender. 



Thorax. Pronotal scutellum sordid yellow; scutum hair}-, darker in middle 

 portion. ISIesonotal praescutum without hairy vestiture, gray ish-prui nose, 

 stripes blackish, broad, the median stripe divided by a dark line, the lateral 

 stripes indistinctly prolonged upon the mesonotal scutum. Scutellum and 

 postnotum grayish-white pruinose with dark median line. Pleura, with the 

 exception of the upper part of the mesopleural sclerite, densely grayish- 

 wloite pruinose; pleuro-dorsal membrane dark yeUowish-browTi. 



Legs rather robust, of moderate length, broAvn; coxae densely grayish- white 

 pruinose, femora j-ellowish-browm, darker towards the apices, pubescence very 

 short, black, appressed; tarsi black. Halteres dark brown, yellowish at base. 

 Wings grayish, broad; Cells C and Sc yellowish, stigma pale yellowish- 

 brown; vein R setulose, vein Sc^ atrophied; venation as in figm-e. 



Abdomen grayish-pruinose except along the dorsum, where its ab.sence leaves 

 a broad black stripe of the ground color; the extreme posterior margin of 

 segments three to eight, whitish, the lateral margins more broadly, yellowish- 

 wlaite. Eighth sternite with a slight emargmation in the middle and one on 

 each side. Hj-popygimn blackish, appendages ferruginous; ninth tergite very 

 short, impressed anteriorly, posterior margin emarginate in the middle, lateral 

 angles acute, upper appendages broadly lanceolate, inflexed; ninth sternite 

 with closed suture; pleural suture absent. PI. V, fig. 21. 



Female. Length, 13 mm.; wing, 12 mm. 



Very similar to the male. Antennae shorter and less markedh^ denticulate. 

 Sides of scutellum and postnotum yellowish. The lateral margin of the ab- 

 dominal tergites scarcely at all paler. Ovipositor ferruginous, dorsal valves 



