42 Elementary Manual of Zoology. 
Solitary wasps build cells much like those made by solitary bees ; 
they store these cells with insects or spiders which they paralyse, but 
do not kill, by stinging them. When the cell is stocked, and the ege 
laid, the parent wasp closes it up and leaves its larva to develop alone. 
The parents are said to die off before the young emerge from the cells. 
The students can usually see solitary wasps at work building and 
stocking their nests in the school compound, 
Fossoria (Sand-wasps).—This group comprises several families. The 
insects are smooth-bodied, often long-legged creatures, much like 
wasps in appearance. They can be distinguished from wasps by thei! 
antenne, which are often curled but not elbowed. In habits they are 
very much like solitary wasps. They may frequently be seen dragging 
along paralysed grass-hoppers and other insects as big or bigger than 
themselves, in order to store them in cells for their young to feed 
upon. The Museum contains numerous specimens. 
Scoliida.—These insects are hairy creatures, frequently of considerable 
size. They often have much superficial resemblance to bees, but can be 
readily distinguished from these insects by their posterior tibie and 
tarsi, which are not modified for pollen-carrying. Little has been 
observed in connection with their habits in India, but both in Europe 
and Madagascar representatives of the family have been observed to 
lay their eggs inthe larve of the rhinoceros-beetle (Oryctes). It is 
likely therefore that the species of Scoliide whieh occur in India 
will be found to havesimilar habits, In this case they must be to 
some extent beneficial, as every beetle larva that is parasitised perishes. 
The School Musuem contains specimens for examination. 
V1.—Diptera. 
The Diptera comprise the two-winged flies. They may be defined 
as insects which pass through a well-marked pupal stage, have their 
mouth parts modified for piercing and sucking, the hind wings rudiment- 
ary, and the front wings, when present, membranous, There area 
great number of species in India, many of the forms being vastly 
numerous in individuals. One of the easiest features for recognising a 
dipterous insect is the peculiar little pair of rudimentary hind wings 
which are present in the great majority of species and which are said to 
serve as organs of sense. 
The mouth parts consist of the labium, which usually forms a sheath 
for the style-like mandibles, maxille, and hypopharynx. These style- 
like piercing organs are much developed in insects like the mosquito and 
the flea, which live by blood-sucking, but are rudimentary in the house- 
fly, which is therefore only able to suck up fluid with its flexible tubular 
labium, 3 
