﻿22 F. W. EDWARDS — A SYNOPSIS OF THE SPECIES OF 



This is a variable species, and not very easy to recognise. Between extreme 

 forms there is considerable difference in the colour and form of the scales, but I 

 can find no constant differences between the forms enumerated above, and so have 

 included them all as one species under the oldest name. I may be wrong in this, 

 but if there is more than one species more material and more minute study will 

 be required before they can be properly separated. It is with some reluctance 

 that I accord specific rank to O. africanus, Newstead (described from one female) 

 and O. abnormalis, Theo. (described from two males, one dissected). The most 

 characteristic features of the different forms may be briefly pointed out. 



i. Typical form (minutus). Head bearing flat scales over the occiput ; scales 

 dark in the middle and at the sides, leaving a V-shaped pale area. Pale scales 

 of thorax forming a pair of distinct spots about the middle of the mesonotum. 



ii. var. tar sails (= bipunctatus). Like the type form, but without flat scales 

 over the top of the head, the scales in this position being narrow and curved. 

 This difference, which is regarded as of generic value by Theobald, is not con- 

 stant, and intermediates occur between these two varieties. Some specimens 

 from Uganda are larger than those from Ashanti and have the pale spots on the 

 thorax less marked ; the integument is dark brown instead of red-brown. 



iii. var. biannulatus (= neobiannulatus). Head scales all pale in the middle ; 

 thorax without distinct pale spots, though the light and dark scales are not evenly 

 mixed ; abdomen of female sometimes with traces of pale bands at the bases of 

 segments (lateral white spots are always present), it. neobiannulata was proposed 

 by Theobald, without any apparent reason, as a substitute for JR. biannulata, 

 which was founded on some males from Sierra Leone. Although the female of 

 R. biannulata was undescribed, we were given characters by which it might be 

 distinguished from R. neobiannulata, and also the male genitalia of the two were 

 said to differ, even though both names were given to the same specimens. 



iv. var. uniannnlatus. Like the preceding, but there are some narrow scales 

 on the apical portion of the middle lobe of the scutellum. 



v. var. stenoscutus, nom. nov. (= africanus, Theo., nee 0. qfricanus, Newst.). 

 This is the most distinct of the varieties of this species. The abdominal seg- 

 ments of the female have distinct pale basal bands ; the scutellum bears a 

 considerable number of narrow scales, mostly on the middle lobe (but this 

 character is variable) ; the hind femora are whitish beneath on the whole of their 

 length (in the other varieties they are usually darkened towards the apex on the 

 under side) ; in some specimens the white spot at the apex of the hind tibiae is 

 rather indistinct. 



Sierra Leone ; Ashanti ; Gold Coast ; Uganda ; Congo ; Angola ; Sey- 

 chelles Is. 



21. 0. abnormalis, Theo. (Bathosomyia), Mon. Cul. V, p. 238 (1910). 



The hind claws (c?) are unequal and simple. The genus Bathosomyia seems to 

 have been founded principally on the characters of the male genitalia ; but in 

 the single mounted specimen these organs cannot be properly made out. They 

 seem to be similar to those of the preceding species. 



Ashanti. 



