966 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXV III ^ 
remains external, enjoying a free and, let us hope, merrier life. He 
is a normal pupiparous fly in habits, structure and development 
similar to other Streblids. The reader who is an entomologist will 
at once think of an analogous case where the female of a parasitic 
insect buries herself in the flesh of the host, namely the jigger flea, 
Derniatophilus, of hot countries. 
The distribution of the Streblids is not at all accurately known. 
Nycteribosca gigantea, Speis., has been taken off bats in the caves of 
Burmah. Two species of Raymondia, Frfld., have been collected in 
Madras. There must be numerous species in India if they were 
searched for, since bat parasites have been so little collected. 
Nycteribiidce. The members of this family are wingless flies para- 
sitic on bats ; and it follows that the ordinary person who does not 
make a special business of collecting bat-parasites is unlikely ever 
to come across them. The family is an extremely interesting one 
because of the extraordinary morphological modifications which the 
typical Dipterous structure has undergone under the influence of a 
highly specialised parasitic existence. These insects pass almost the 
whole of their lives on the bat’s body and derive the whole of their 
nourishment from its blood which they suck at frequent intervals. 
The Swedish naturalist, Linnaeus (1758), thought that they were 
lice. Latreille (1795) established the genus Nycteribia. This emi- 
nent French entomologist also saw that these insects were, in fact, 
wingless flies and not lice. The ordinary unlearned person might 
mistake them for small spiders, which they somewhat resemble both 
in form and in manner of movement. 
The Nycteribiidae have an almost world-wide distribution. Bats 
are found all over the globe except in the Polar regions. It would 
seem that all sorts of bats are at times infested with these parasites. 
An individual bat may harbour Nycteribiids belonging to two diffe- 
rent genera ; and several species of these iirsects have frequently 
been taken from, the same species of bat. The migratory powers 
of the hosts are sufficient to explain the wide geographical distribu- 
tion of these parasites. Nine different species of Nycteribiid have 
been collected from one form of bat which has an exceptionally wide 
geographical range. It is a well established generalisation that these 
bat parasites have their headquarters in the Old World and are most 
abundant in the countries which lie round the Indian Ocean. Speiser, 
who is again the greatest authority on the family, recognises some 
eight genera and between thirty and forty species.* The genus Archi- 
* Tn his learned and painstaking paper there ■will be found a full bibliography 
of the literature down to 1901 and a summary of our knowledge of the group together 
with a revision of the family and a table to show the geographical distribution. See 
“ Ueber die Nycteribiiden, Fledermaus Parasiten aus der Gruppe der pupiparen 
Dipteren.” Von cand. med. P. Speiser. Archiv fur NaturgeschicJite (1901) CGth yea 
Vol. I, p. 11. 
