336 
COLEOPTERA. 
ventral retractile process ; the legs are present and functional in run¬ 
ning. The larvae are extremely difficult to find ; Opatrum is in some 
places found literally in millions but its larva never ; larvae have been 
obtained first in captivity and then in the field only after prolonged search¬ 
ing. The known larvae, like the known beetles, feed on dead vegetable mat¬ 
ter such as decaying leaves ; this also appears to be their food in desert 
places where there is a layer of leaves below each bush ; we have seen 
these desert forms come out in numbers and feed on locust hoppers. 
The function of the family essentially is that of scavenging the dead 
vegetable matter that falls in such abundance and, excluding the house¬ 
hold pests, none are injurious. The prevalence of deep black as a 
colour is to be expected since they are insects which shun light and 
which live in dark places where they are well hidden; the colouring 
strikes one when one sees these beetles in sandy deserts as in North 
India, but the colouration is of use since the beetles rapidly recover 
from the torpidity due to the chill of the air at night by coming out 
into the sunlight at sunrise for a short time before going into the bushes 
to feed. These beetles are a striking feature of the sandy wastes of 
North India where insect life is so scanty and these species are very 
imperfectly known and probably peculiar to such localities. Not all 
Tenebrionids live on the soil in concealment, though most do so ; they 
really fall into two series, the light-seeking and the light-shunning 
species, the latter predominating. They are found among decaying 
vegetation, among fallen leaves, under bark, in thatched roofs, between 
the timbers of a house and generally in concealment. Practically 
nothing is known as to the length of their life-histories or their seasons ; 
a yearly feature is the emergence of numbers of the very common beetle 
Mesomorpha villiger , which breeds in dry leaves and wood and which 
emerges abundantly to fly in the warm evenings in March in the plains. 
In the warm winter of 1907, these beetles emerged on February 25th, 
an exceptionally early date. Opatrum appears to have no season, nor 
do most of those which we have found abundantly in the plains, though 
Blaps is found only in the co ] d weather and probably has a yearly 
period. 
The family is a very large one with a great number of species. The 
geographical distribution is wide, but the ground species appear to be 
most abundant in Africa, the Mediterranean and Caspian littoral, and 
