14 
Ohservations on British Rat-fleas 
Hystrichopsylla talpae {Pulex talpae Curtis, 1826). 
H. talpae was found on two rats caught alive in Dedham and 
Hollesley, respectively, and on one found dead in Lawford. Its other 
hosts are as follows; 
Microtvs arvalis. Talpa europaea (its true host). 
,, agrestis. Sorex araneus. 
Ctenocephalus canis {Pulex canis Curtis, 1826-1832). 
This species, the common dog Ilea, was twice found by ns on rats in 
Kesgrave and Tuddenham. Three specimens were caught on a dog at 
Holton. Its other hosts are Otocyon megalotis, Canis lagopiis, Nasua 
solitaria and Felis jaguarondi-, and it has been found in the nest of the 
great tit, Partis major. 
Ctenophthalmus bisoctodentatus (Kolenati, 1862). 
Two specimens of this species were found by us on rats in Great 
Horksley and Bentley, whilst two others were taken from a rat in 
Hollesley. 
Ceratophyllus gallinae {Pulex Schrank, 1804) 
Rothschild, 1900. 
This is the flea which infests fowl and poultry runs. It readily 
attacks man—a fact well-known in the country. Its normal host must, 
however, be considered to be the domestic fowl; but its tastes seem to 
be catholic, as it is found in the nests of many species of birds. In 
Cambridge, for instance, we have found it in a number of tits’ nests 
{Parus major). It has also been taken from the bat {Vesperugo 
noctula) and from the field mouse {Mas silvaticus), but it has not, 
hitherto, been found on the rat. This is evidence that the rat cannot 
be regarded with favour by this flea, for the two must often be brought 
into contact in the farm-yard. Indeed, we have caught a batch of rats 
(Holton) in a barn literally swarming with C. gallinae, but they did not 
harbour a single flea of this species. Only on two occasions did we find 
this flea upon rats: once upon a rat caught alive in Rushmere and once 
upon a rat found dead in Bentley. We have taken it several times from 
man in large numbers, also from the dog once (at Holton), and, finally, 
from barns and the hole of an old oak tree. 
