THE MALACODEKMATA. 
183 
elevated, and they have no eyes. The pupa is formed 
near the mouth of the burrow, which is enlarged by 
the larva ; and is thin and cylindrical, as in most wood- 
feeding insects. 
Hylecsetus dermestoides (Plate IX., Pig. 6, male), 
found at Rannoch, Sherwood, &c., differs considerably 
in the size and colour of its sexes, and possesses an 
occllum on the vertex. The maxillary palpi of the 
male are of great size, assuming the appearance of a 
fan, on account of the third joint (which is much 
developed) having numerous branchial appendages. 
In this genus there are six segments to the abdomen ; 
but in Limexylon, which is of the greatest rarity hero, 
though so common on the Continent as to commit 
great damage to timber, there aro only five. 
The CissiD/E or CioiDAi (described by M. Mellie in 
tho French “ Annales,” 1848, p. 205, cl seq.) have 
four joints to the tarsi, of which tho three first are 
not so long as tho apical. Their head is more or 
less retractile within tho thorax, tho front of which 
often projects; the antennm vary from eight to ten 
joints in tho British genera, but have always a tliree- 
jointed club ; the organs of the mouth aro but little 
developed, tho mandibles only being robust, and the 
labrum distinct ; there are no apical spurs to the 
tibiso ; and the first joint of the abdomen is longer 
than any of the others. 
They are all small, cylindrical, feebly built insects; 
varying from yellow to dark brown in colour; gene- 
rally shining, but sometimes clothed with a very short 
silky down, which imparts a somewhat metallic re- 
flection. Their punctuation is almost always irregu- 
lar on tho elytra; and they occur gregariously in 
