96 
BKITISH BEETLES. 
F.fuliginosa, is strikingly like that ant in appearance ; 
and, with others of its genus, acquires a very pungent 
odour, from constantly living in an atmosphere im- 
pregnated with formic acid. It is possibly from this 
cause that these species so often stain with purple the 
card on which they are mounted. 
The species of Ilyobates, Callicerus, &c., are spe- 
cially remarkable for the development of their antennas, 
of which the terminal joint is often of great length in 
the male. They occur rarely in sand-pits, &c. 
Tachyusa constricta, a slender, graceful insect, found 
in wet shingle on the banks of rivers (especially the 
Mole, near Leatherhead), has a peculiar appearance, 
owing to its very “ pinched-in ” waist \ when alive, 
like the greater part of this family, it curls its abdo- 
men upwards and forwards, and runs with great 
quickness. Perhaps, however, the most curious in- 
stance of this curling propensity is afforded by Buce- 
phalus complicans, a small black species found in 
rotten fungi, &c., and about as unlike the insect last 
mentioned as possible, being extremely " squab ” and 
flat : it is not very common, and may be easily passed 
over by a novice, on account of its turning its abdo- 
men entirely over its back, and thus (when not in 
motion) looking more like a small black seed than a 
beetle. The species of Gyrophsena, minute bright- 
coloured insects, also occurring (gregariously) in 
fungi, and very closely allied to Bucephalus, have a 
similar habit, though in a rather less degree : they 
are difficult to determine, but may generally be dis- 
tinguished inter se by the rows of punctures on the 
thorax. Pull English descriptions of our species, by 
Mr. G. R. Waterhouse, are to be found in the Trans- 
