SCHENCK.
Ceratina chalcites, GERM.
Ceratina albilabris, FAB.
Ceratina callosa, FAB.
Ceratina coerulea, VILLERS.

2. HUNTING HYMENOPTERA.
Solenius vagus, FAB. (provisions, Diptera).
Solenius lapidarius, LEP. (provisions, Spiders?).
Cemonus unicolor, PANZ. (provisions, Plant-lice).
Psen atratus (provisions, Black Plant-lice).
Tripoxylon figulus, LIN. (provisions, Spiders).
A Pompilus, unknown (provisions, Spiders).
Odynerus delphinalis, GIRAUD.

3. PARASITICAL HYMENOPTERA.
A Leucopsis, unknown (parasite of Anthidium scapulare).
A small Scoliid, unknown (parasite of Solenius vagus).
Omalus auratus (parasite of various bramble-dwellers).
Cryptus bimaculatus, GRAV. (parasite of Osmia detrita).
Cryptus gyrator, DUF. (parasite of Tripoxylon figulus).
Ephialtes divinator, ROSSI (parasite of Cemonus unicolor).
Ephialtes mediator, GRAV. (parasite of Psen atratus).
Foenus pyrenaicus, GUERIN.
Euritoma rubicola, J. GIRAUD (parasite of Osmia detrita).

4. COLEOPTERA.
Zonitis mutica, FAB. (parasite of Osmia tridentata).

Most of these insects have been submitted to a learned expert, Professor
Jean Perez, of Bordeaux. I take this opportunity of renewing my thanks
for his kindness in identifying them for me.--Author's Note.)

They include members of very diverse corporations. Some, more
industrious and equipped with better tools, remove the pith from the dry
stem and thus obtain a vertical cylindrical gallery, the length of which
may be nearly a cubit. This sheath is next divided, by partitions, into
more or less numerous storeys, each of which forms the cell of a larva.
Others, less well-endowed with strength and implements, avail themselves
of the old galleries of other insects, galleries that have been
abandoned after serving as a home for their builder's family. Their only
work is to make some slight repairs in the ruined tenement, to clear the
channel of its lumber, such as the remains of cocoons and the litter of
shattered ceilings, and lastly to build new partitions, either with
a plaster made of clay or with a concrete formed of pith-scrapings
cemented with a drop of saliva.

You can tell these borrowed dwellings by the unequal size of the
storeys. When the worker has herself bored the channel, she economizes
her space: she knows how costly it is. The cells, in that case, are all
alike, the proper