STUDIES ON EARTHWORMS. 21S 
Studies on Earthworms. 
By 
William Blaxiand Benham, B.Sc., 
Demonstrator in the Zoological Laboratory of University College, London. 
INTRODUCTION. 
In this series of papers I intend to describe a number of 
Earthworms from various parts of the world, which have been 
kindly put into my hands for the purpose by Professor Ray 
Lankester. These include some new genera, with interesting 
variations from allied forms, and several new species of Peri- 
cheta. But before describing these new forms I shall give— 
firstly, a condensed historical review of the various works on 
Earthworms, and achronological record of the discovery of new 
facts about them. 
Secondly, I shall enumerate and briefly describe all known 
Earthworms. 
Thirdly, I shall take the various organs in order and point 
out their variations in different Earthworms, and the theories 
of various authors with regard to certain points. 
Having done this, I shall proceed to describe the new forms 
that I have studied myself. 
I wish to thank Professor Lankester for his kind advice and 
assistance in this work, which was carried on in his Laboratory 
at University College, London. 
I shall not give an exhaustive bibliography, since that will 
be found in Perrier’s work on Urocheta (28), but I shall 
in all cases give references for any facts I mention to a biblio- 
graphy at the end of the third section, the figures in brackets 
referring to this bibliography. 
