44 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
y. Platyhelminth.es. 
Geonemertes australiensis.* — Dr. A. Dendy gives an account of 
this, the fourth known species of Land Nemertine ; its minute anatomy 
is found, on comparison with Burger’s researches on the marine 
Nemertea, to agree very closely with the marine forms, and especially 
with the Enopla. The circulatory system, however, appears to be 
merely a specialized portion of the excretory system. This last exhibits 
the most striking and important differences, for it consists of a system 
of intracellular tubules terminating in flame-cells. There is this 
objection to considering the network of tubules as excretory, that the 
author was unable to find any opening whatever to the exterior ; it is 
possible, however, that it has been missed among the numerous genital 
apertures with which this animal is provided. The flame-like undu- 
lating structure connected with the tubules was, fortunately, seen in a 
crushed preparation of a living worm ; its movements were extremely 
beautiful and characteristic, consisting of a series of undulations passing 
from base to apex in rapid succession, and causing the “ flame ” to 
exhibit alternate light and dark bands, and to give, at first, the impression 
of bubbles of gas escaping from the end of a tube under water. The 
flame appears to be made up of a bundle of long cilia, for faint indi- 
cations of longitudinal striation were visible in it. With the possible 
exception of Tetrastemma aquarum dulcium, described by Silliman 
in 1885, this is the first time that flame-cells have been observed in 
Nemertines. 
The present form differs from the three other known Land Nemertines 
in the presence of a large and indefinite number of eyes, the others 
having four or six. In G. australiensis there may be as many as thirty 
or forty, and there are indications that they may have arisen by the 
subdivision of four eyes ; these eyes are sometimes dumb-bell-shaped, 
which is an indication that they multiply by division. 
Burger is in error in stating that all Land Nemertines are herma- 
phrodite, for this is not correct of either known species of Tetrastemma 
or of this new species. In it the females appear to be much commoner 
than males. The ova communicate with the exterior by narrow ducts 
which open along the sides of the body, and appear to allow of the 
entrance of spermatozoa, for which there are, in the male, numerous 
ducts. Both ovaries and testes are extremely numerous, and occur 
thickly scattered along the sides of the body. 
G. australiensis is about 40 mm. long and 2' 5 mm. broad when 
crawling. It is chiefly yellow in colour ; the skin contains no rod- 
like bodies, but irregularly oval calcareous bodies lie in the deeper 
tissues. 
Freshwater Nemertine in England, f — Dr. W. B. Benham has 
found in the river Cherwell, close to Oxford, a single specimen of a 
freshwater Nemertine, which may be Tetrastemma aquarum dulcium , but 
differs in some points from the description given by Silliman of that 
worm. 
* Proc. Roy. Soc. Victoria, 1891 (1892) pp. 85-122 (4 pis.), 
t Nature, xlvi. (1892) pp. 611 and 12. 
