200 TlMEHRI. 
cases shown, the work of determination is rendered 
thereby very doubtful. 
The reserve collection of Birds, which now numbers 
about 2,000 specimens (exclusive of the specimens ex- 
hibited in the cases), has been entirely revised and re- 
arranged, so as to be easily available for reference or 
study— and similar work is about to be taken in hand 
for other groups, particularly that of Insects. This 
group presents a case of most exceptional difficulty, for 
apart from the lack of assistance in the Colony, no writer 
in recent times has yet been able to devote time except to 
extremely scrappy descriptions of the Guiana forms. 
This lack of descriptive work is a sore trouble to the 
systematist, and renders it almost essential in all cases 
that specimens be sent to the United States or to Europe 
for identification and comparison with named series. 
This difficulty is not easily overcome, for if large collec- 
tions be sent, persons can scarcely be got to undertake 
their quick and certain identification, and then only by 
the retention of the specimens which are thus lost to the 
Museum ; or if paid assistance be obtained, this is often 
costly and but little to be relied on for specific accuracy. 
Something, however, is being done with the group, and 
I trust that at a not very distant date, it will have been 
made possible to have a well arranged and classified set. 
The larval stages and development of many of these 
forms are quite unknown, and as a commencement to- 
wards a contribution to the history of the Guiana Insects, 
an attempt is being made to get together coloured 
figures of the early stages of the Lepidoptera, to be 
published later on with descriptive sheets. In this con- 
nection it gives me special pleasure to acknowledge 
