HORSEFLIES OF THE SUBFAMILY TABANINAEH 163 
Abdomen blackish above, with three rows of gray spots and narrow bands, 
sometimes tinged with yellowish brown but the sublateral spots not very large 
and confluent; venter mostly dark, with grayish incisures. 
Male.—Unknown to the writer and not sufficiently well described to permit 
distinction between this and related species. 
Type.—aA female, probably in the Berlin Museum. 
Type locality —Labrador. 
Distribution —Alaska to Labrador and south to Colorado, Minne- 
sota, and Quebec. June 10 (Anchorage, Alaska) to September 1 
(Leadville National Forest, Colo.). In the United States National 
Museum, 274 females. 
This species shows some variation, and attempts have been made 
to give the variations specific value. Specimens from Labrador, the 
type locality, are somewhat darker, and there is usually black hair 
on the first palpal segment, as mentioned in the original description, 
as well as more black hair on the thorax and abdomen than in 
specimens from the more western portion of its range. The writer 
has examined the type of Zabanus canadensis Curran and does not 
feel that the name should be used even for varietal status. 7. 
frontalis Walker is also extremely close and may not deserve specific 
status, but for the present the writer prefers to consider it distinct. 
Whether Enderlein correctly determined septentrionalis when he 
placed it in the genus Tylostypia is open to considerable doubt, since 
the stump from vein R,, characteristic of Z’ylostypia, is rarely present. 
This is one of the economically important species of the North 
and West. 
UNRECOGNIZED SPECIES 
Tabanus calens Linnaeus, Systema Naturae, ed. 12, v. 1, pt. 2, p. 1000, 1767; 
Degeer, Memoires pour servir a l’histoire des insectes, v. 6, p. 226, 1776; 
Fabricius, Entomologia Systematica, v. 4, p. 364, 1794; Wiedemann, Ausser- 
europaische zweifliigelige Insekten, v. 1, pp. 184-185, 1828; Osten Sacken, 
Mem. Boston Soe. Nat. Hist. 2 (pt. 4, No. 4) : 472, 1876. 
Type.—Sex and collection, if still in existence, unknown. Orig- 
inally in the Degeer collection. 
Type locality —America. 
Considerable confusion exists as to the identity of this species. 
Degeer places it as a synonym of his Zabanus giganteus, although 
the original description, brief as it is, makes this very doubtful. It is 
quite probably one of the /iéneola group and may be either Nearctic 
or Neotropical. There is little likelihood that the type could be 
recognized as the type, if found, and the original description is far 
too brief to make recognition possible. 
Tabanus comes Walker, List of the Specimens of Dipterous Insects in the 
Collection of the British Museum, pt. 4, p. 1152, 1849; Philip, Canad. Ent. 
68: 156, 1936. 
Tabanus inscitus Walker, List of the Specimens of Dipterous Insects in the 
Collection of the British Museum, pt. 1, p. 172, 1848. (Preoccupied by 
Tabanus inscitus Walker, p. 161.) 
Cotypes.—Two females, in the British Museum. 
Cotype localities—St. Martin’s Falls, Albany River, Hudson’s 
Bay; Nova Scotia. 
This is perhaps Z'abanus astutus Osten Sacken, but an examina- 
tion of the types, from which the heads are missing, would be neces- 
