Xll. 
(from Latin domesticus ) relates to the house. As Dermestes lardavius 
perhaps is oftener found indoor than out, the term “ domestic ” is in a 
certain sense applicable, more especially as the Latin lardanum refers 
to a larder. 
Both beetle and larva of this species are plentiful in City warehouses, 
and with but little trouble one can obtain a good supply of them. 
Provision dealers are sometimes greatly troubled with them, and I 
have no doubt they could be obtained in almost any number throughout 
London. The larva is a fast runner, and can be found all through 
the year. It will feed on the hard skin and refuse of meat, making 
curious galleries by throwing up a yellow waxdike substance all round 
its food. It is difficult to tell the pupal stage, as in most cases 
the pupa is formed within the skin of the larva, and it still retains a 
certain ‘power of motion in the legs. The beetle forms rapidly, 
and generally makes its appearance in two or three days after changing 
to pupa. On emerging, the pattern of the wing cases is at once 
discernible, although the beetle is of a slightly paler colour. The 
pupal shell is probably devoured by the beetle, as I have never found 
much of it left. 
Among other beetles frequently occurring in the City are the so- 
called “ bookworm ” species. These all belong to the group Ptinidas, 
and include the following species :— Niptus hololeucus, Mezium affine , 
Gibbium scotias, Anobium paniceum, A. domesticum , Xestobium tessellatum , 
and Ptinus fur . 
As reference has frequently been made to species of Bookworms in 
the “ Publishers’ Circular ” and other publications, it will not be out 
of place to give some particulars respecting the life-histories of these 
species, as observed by myself in a City printing office. In the first 
place it must be stated that the reports concerning the ravages of 
bookworms are nearly always from persons who appear to be 
unacquainted with the rudiments of Entomology, and possibly the 
statements as to the damage done by these species are greatly 
exaggerated. But real harm may occur where books and 
bookshelves are entirely neglected, and where dust and moth doth 
corrupt, and beetles and cockroaches roam without let or hindrance, 
while with due care and attention this would be entirely obviated. 
In the British Isles, at least, little danger should be apprehended from 
bookworms. But in warmer countries, where cockroaches and white 
ants abound, then extra precaution is highly necessary. As we are 
concerned only with bookworms which affect our own country I will 
now proceed to deal with them specifically. 
In endeavouring to trace the origin of the term of “ Ptinus ” my 
labours have proved almost futile, as indeed is the case with many 
