THE GIANT FLEA: HYSTRICHOPSYLLA TALPAL, 257 
he has little doubt that the great numbers of specimens he had himself 
observed on the cliffs belonged to the swarm that his daughter had 
seen arrive that morning. 
The habit which butterflies have in calm weather of settling on the 
sea when migrating, has been observed by many entomologists. 
Pocklington records (Hntom., vi., p. 152) that in May, 1872, he 
watched several Pieris brassicae flying far from the shore in Boston 
Deeps (Wash), and observed one of them apparently fall in the sea, 
when, to his surprise, as the wave arose upon which it had alighted, 
the butterfly mounted with it and flew away uninjured and apparently 
refreshed by its resting there. The habit is important, as helping to 
explain the physical ability of certain species to travel what would 
otherwise appear to be almost impossible distances. A too frequent 
resting, however, would appear to be fatal, for it has been recorded 
more than once that, when thus resting, although they are able to 
rise a few times with ease, yet the scales soon get wet and then the 
insect has some difficulty in rising again, and when the power fails it 
necessarily perishes. We have already detailed (supra) occurrences 
when large numbers of lepidoptera have come to erief on one of 
their voyages, but this must not be taken asin any way disproving 
the general fact of their ability to rest on the surface of the 
water. This failure has been noted in such _ strong-winged 
species as Anosia archippus, Pyrameis cardui and others, and it 
is probable that the attempt to rest once too often is sometimes the 
cause of the large number of dead lepidopterous insects which are 
occasionally observed floating on the surface of the water at various 
times and in different places. The ability, however, that butterflies 
have to rest in this manner has led to the suggestion that the butter- 
flies, which periodically migrate between Ceylon and India, avail 
themselves of the habit whilst crossing. 
The Giant Flea: Hystrichopsylla talpae (with plate). 
By the Hon. N. C. ROTHSCHILD, B.A., F.L.S., F.E.S. 
Entomologists, particularly coleopterists, from time to time come 
across the giant flea (Hystrichopsylla talpae). This insect would 
probably escape notice altogether were it not for its phenomenal size, 
it is in fact the largest species hitherto recorded, being no less than 
5:5 mm. in length. During the last few years I have received several 
specimens of this insect from British entomologists, and as a slight 
recompense for their kindness I have endeavoured to give an accurate 
ficure of one of the strangest British insects. 
The Siphonaptera, though possibly the most succinct and highly 
specialised group of insects found in Great Britain, have hitherto 
received but little attention from English entomologists. The 
accompanying figure, drawn by my friend Dr. Jordan, will no doubt 
interest those entomologists who have captured specimens of H. talpae, 
and may possibly induce others to give attention to this very interest- 
ing family of parasitic insects.  Hystrichopsylla talpae was originally 
described and figured by Curtis*, and has been figured again by 
* Brit. Ent., iii. (1826), no. 114, Fig. 
