ENTOMOLOGY 929 
the head and thorax are black, covered with brown tomentum, sometimes with 
paler lines on the dorsum; the median pale spot is almost always present on 
the third and fourth abdominal tergites. 
This beautiful and easily recognizable species is distributed over the entire 
Ethiopian Region, from Mauretania to the Anglo-Egyptian Sudan and the Cape. 
As earlier mentioned by Loew and more recently confirmed by Austen, it ex- 
tends into Southern Arabia, as is, moreover, the case with many other truly 
Ethiopian forms of life (Belonogaster, Glossina, African anophelines, etc.). In 
addition to its striking sexual dimorphism, the insect varies somewhat locally 
in the color of the palpi and of the hair of the head and back of the thorax; 
while the abdomen of the female may or may not have the median white spots 
on some of the segments, which are almost always present in the male. 
Sureouf in his monograph of African Jabanus (1909) has attempted to 
distinguish local races based upon these variations. Unfortunately his account 
is very confused and his use of the names proposed by other authors is to some 
extent erroneous. 
On page thirty-eight of his Monograph Surcouf says that the type of Ta- 
banus biguttatus Wiedemann no longer exists and ‘‘was described by the author 
in the following terms.’ He then quotes a short description of both sexes 
which, however, is not Wiedemann’s, but Loew’s (1860). Wiedemann origi- 
nally described biguttatus upon the male alone, from the Cape. Tabanus cerberus 
Walker (¢), 7. noctts Walker (~), and YT. tripunctifer Walker (¢), all de- 
seribed from South Africa, are synonyms of the typical biguttatus. In each case 
the description mentions that the wings are brown-black with cinereous apex. 
In 1838, Macquart described a Tabanus cilipes which, as pointed out by 
Loew, was a composite form. The Latin diagnosis and the first French de- 
seription were drawn from a male of the Cape and apply exactly to Wiedemann’s 
T. biguttatus. Macquart then proceeded to describe several males from Senegal, 
one female ‘‘brought back from Africa by Lalande” (consequently of South 
Africa), and another female of Serville’s collection, of unknown provenience. 
Of these, Lalande’s female belongs to typical biguttatus; while the males from 
Senegal and Serville’s female are the form which Macquart had previously 
(1834) called 7. wnimaculatus. Surcouf’s conclusion (1909, page 42) that 
T. cilipes Macquart is a synonym of unimaculatus Macquart does not, there- 
fore, cover all the facts in the case. 
The foregoing discussion is not entirely without interest, for in the ‘Genera 
Insectorum’ (1921) Surcouf lists Tabanus unimaculatus Macquart as a species 
distinct from Tabanus biguttatus Macquart; while under the latter name he 
indicates two varieties: cilipes Macquart and croceus Sureouf. In a later 
paper (1922, ‘Voy. M. de Rothschild Ethiopie, Rés. Scientif., Anim. Artic.,’ 
II, p. 845), he further increases the confusion in apparently distinguishing 
three varieties, wnimaculatus, cilipes, and croceus, from typical biguttatus. 
In 1907, Surcouf described a var. croceus which, he says, ‘‘has the size and 
general aspect of 7’. v. wnimaculatus Macquart and differs from it in the yellow- 
his pubescence which extends over thorax, scutellum, frontal band, cheeks, 
