INTRODUCTION. 
By P. VAN DER Goo. 
The following pages contain a somewhat shortened account of a very thorough 
and interesting study on the Aphididae of Lahore by the late Mr. Das, which study 
originally was submitted asa thesis for his Doctorate in the Punjab University. Mr. 
Das’ sudden death unfortunately prevented the publication in full of his valuable 
paper. Financial reasons making it impossible to publish the study as a whole in the 
_“ Memoirs of the Indian Museum,’’ the writer was consulted by Dr. Annandale, now 
Director of the Zoological Survey of India, as to the possibility of publishing those 
parts of Mr. Das’ paper that might contain any information either new or interesting 
to science. 
After having looked through the manuscript of the late Mr. Das’ paper, it was 
thought advisable to omit from the original paper all descriptions of recorded species 
that had already been sufficiently dealt with by other authors. Of the different well- 
known species all particulars available as to their biology in India have however been 
retained in full. The descriptions of different new species are published here in the 
original form as Mr. Das has put them down, although in the writer’s opinion they are 
sometimes a little too lengthy. 
The writer has had the pleasure of being in correspondence with the late Mr. 
Das on different points of systematical questions concerning Aphididae, and, through 
his courtesy , has received specimens of some of the new species, treated in this paper. 
Being therefore in the position of comparing my own notes on these species with the 
descriptions of Mr. Das, I have sometimes thought it necessary to add in short a few 
corrections or additions. In some cases I have thought it advisable to add in a 
separate note my own opinion on some questions of nomenclature or systematics. 
The original descriptions themselves have, however, been left untouched as much as 
possible. 
In my opinion Mr. Das’ paper will prove of great value to our knowledge of 
tropical and subtropical Aphididae, a subject which until very recently has been 
practically left untouched. His pioneer-work undoubtedly will give his fellow-workers 
many a good addition to their knowledge of this interesting group of little insects. 
Salatiga, November ıoth, 1916. 
Lt.-Col. J. Stephenson, I.M.S., Principal and Professor of Zoology, Government 
College, Lahore, has kindly supplied the following biographical note :— 
““ Bashambar Das was born in 1884 at Nainakot, Gurdaspur district, where his 
father was a teacher in the local school. He received his early education at Rahon 
