THE HABITS AND NATURAL HISTORY OF 
STICHOSTEMMA. 
C.2M>CGHILD. 
A SMALL fresh-water nemertean, undoubtedly .Szzchostemma 
asensoriatum Montgomery (96), is found very abundantly in 
one of the park lagoons in Chicago. 
The animal has proved to be a favorable form for experi- 
mental study, and in the course of such work during the past 
two years a number of observations upon its habits and natural 
history have been made. These observations are given here 
in the belief that a connected account of the natural history of 
a single form is of value because it brings together a series of 
facts which, though important, often receive only incidental 
attention in connection with other work, or are ignored alto- 
gether, and because it affords a basis for further study. 
Montgomery (96) has given a brief description of a new 
American species of fresh-water nemertean which he called 
Stichostemma asensoriatum. He regards Silliman's Tetra- 
stemma aquarum dulcium (85) as insufficiently characterized, 
but believes that it may be closely allied to S. asensoriatum. 
The species which forms the subject of this paper agrees with 
Montgomery's description of S. asensoriatum in all respects 
except that it is not protandric, while Montgomery believes 
S. asensoriatum to be protandric like S. eilhardi. Bohmig 
(98) has accepted Montgomery's genus Stichostemma for his 
species S. grecense, but as S. gr@cense is not protandric, 
Bóhmig holds that the existence of protandry should not be 
regarded as a characteristic of the genus. Ina personal com- 
munication very kindly made in answer to an inquiry of my 
own, Dr. Montgomery expresses himself as of the opinion 
that the presence or absence of protandric hermaphroditism 
is a point of minor importance. The revised genus diagnosis 
of Stichostemma as given by Bóhmig (98) is as follows : 
975 
