Annals of the Transvaal Museum 
223 
Even without knowing the habits of “ Hirundo” dimidiata Sundevall, 
genotype of Hemicecrops Bonaparte, it is obvious from the absence of white 
tail marks that it is not correctly allocated with the true Swallow; and when 
we examine further, we find this confirmed by the eggs being white and the 
bird being reputed to occupy the nests of other birds, characters and habits 
which indicate affinity to the American genus Tachycineta\ but as the 
African species has the tail more deeply forked, Hemicecrops may be 
retained for generic purposes. 
In the Mosque Swallows the tip of the wing does not extend beyond 
the tip of the penultimate tail feather, correlated with which we find the 
species building mud nests, with long tubular entrance, against some over- 
hanging roof or shelter, and the eggs pure white. These species were long 
ago separated under the generic name of Cecropis Boie, type Hirundo 
cuciillata Boddaert, and they are characterised by having the nostrils with 
a narrower superior membrane than in Hirundo, the forking of the tail 
of about the same depth, but the underparts of the body striped. The 
smaller species, H. puella, might be considered subgenerically different. 
The Red-breasted Swallows should, however, be placed in another genus, 
characterised by having the tail more deeply forked and the underparts 
of the body not striped, usually reddish in colour; the nest is similar in 
shape to that of Cecropis but built, as a rule, in a more sheltered situation, 
such as the roof of a hole in a river bank, hollow horizontal branch of a tree, 
though sometimes in culverts also occupied by the stripe-breasted group. 
For this group I propose the name of Phoenichelidon gen. nov., type 
H. semirufa Sundevall. 
In the synopsis of the species in the monograph above mentioned, and 
in the Catalogue of Birds in the British Museum, the Mosque Swallows 
are grouped with the true vSwallows on the character of the nostrils; but 
this is misleading, the former having only a narrow superior membrane 
compared with the latter. Similar disregard for structural characters has 
led astray the allocation of the Grey-rumped Swallow, Hirundo griseopyga 
Sundevall, which differs entirely in its weak and very small bill, the nostrils 
sht-like and wider open than in Hirundo, the forking of the tail much the 
same as in Hirundo, but the “streamer” shorter, and in size and colour 
more nearly approaching the Sand Martins; its nest is also said to be 
situated in a hole in the ground (cf. Sheppard, Journ. S. Afr. Orn. Un. v. 
35, 1918), and doubtless its eggs will prove to be white, the species seeming 
to have an affinity to Hemicecrops. No generic name being available, I 
propose to place the species in a new genus under the name of Pseud- 
HIRUNDO, type Hirundo griseopyga Sundevall. 
Passing now to the species commonly lumped with the Sand Martins, 
it is clear that systematists have in the past been led astray by superficial 
appearance, little regard having been given to structure. The Rock Martins 
are lumped with the Sand Martins, simply because they are plainly coloured ! 
But, having regard to the nature of the nest, eggs, white spots on the tail, 
there seems to be no reason why the Rock Martins should not be placed 
close to the ty^icdl Hirundo, the squared tail distinguishing them therefrom. 
I have frequently observed the species nesting in Pretoria in the height 
of winter, and consider it not unlikely that this habit has some relation 
to its plain coloration, although it breeds of course in the summer as well. 
