Annals of the Transvaal Museum 
9 
Each half of the genital sternite is actually a compound structure in 
both sexes : the parts of which it is composed 
are entirely fused together posteriorly, but 
anteriorly the suture lines can be easily re- 
cognised. The half sternite is therefore in- 
terpreted by Bernard as derived from two 
segments of an appendage incompletely 
separated by interarticular membrane, and 
I may remark that the so-called segmental 
and interarticular regions are somewhat 
different in their coverings of hair : in the 
example figured (. Daesia lineata) the tri- 
angular interarticular portion is clothed 
only with comparatively short fine hairs 
whilst the rest of the sternite bears also a 
great number of much longer and stiffer 
setae which are cleft or even trifurcated at 
the tips. 
In most species, the adult male is characterised by the possession of 
the flagellum on each chelicera. This organ is derived from a socketed 
bristle, and thus the rotatable flagellum of a Blossia presumably repre- 
sents a more primitive condition than that of Solpuga which is fixed. 
Dr Purcell has described an enlarged feather bristle in the genus Melano- 
blossia as a flagellum, and in other genera could find no flagellum what- 
ever in what appeared to be the adult male. It now appears that more 
or less enlarged feather bristles may co-exist with a true flagellum in the 
genus Blossia: this occurs in the species B. falcicornis and B. filicornis, 
where some of the more distal feathered bristles of the series on the 
mesial surface of the chelicera are considerably longer and stronger 
than those proximally situated. Moreover, the position of the point of 
attachment of the flagellum relative to the series of feather bristles is 
very variable : sometimes in the genus Blossia it is at the distal end of 
the line of feather bristles, but in Blossia falcifera it lies between the 
distal enlarged bristles and the dental series, whilst in the genus Daesia 
the base of the flagellum is far removed from the line of feather bristles. 
However, Sorensen, after examining in some detail the structure and 
homology of the flagella of several genera, concludes that morpho- 
logically the flagellum is the superior bristle or the two superior bristles 
of the series. 
I am satisfied that Sorensen's conclusion is quite correct. Not only 
is the original relation to the line of feather bristles retained in the genus 
Blossia, but here too the flagellum is primitive in form, being a greatly 
inflated bristle cut open along its length. The genus Solpuga, which is 
far more specialised, affords confirmatory evidence, although the flagel- 
lum of adults has little resemblance to a bristle. The mesial surface of 
the upper j aw of a very young Solpuga presents two long oblique series 
of bristles, that adjacent to the cutting edge including about 23 bristles, 
all feathered with the exception of the distal one which is fairly long 
but simple : the other series, parallel thereto, consists entirely of simple 
Text fig. 1 a. Genital sternite in 
the adult female of Daesia 
lineata'. flattened out. That 
of the male is similar, but has 
also a pair of elongated scle- 
rites mesially. 
