94 
The Irish Natmatisu 
April, 
A TERATOLOGICAL SPECIMEN OF 
MYRMICA RUBRA. 
BY REV. W. F. JOHNSON, M.A., F.E.S. 
Among some specimens of the above ant, which is 
the common httle red ant so often found under stones, 
I have found a worker which has a most curious develop- 
ment of the propodeal or epinotal spines. These spines 
are two in number and project from the hinder part of the 
thorax backwards over the petiole or waist of the insect. 
They are usually curved and tapering to a point without 
any break in their outline (fig. i). In this particular 
specimen the left-hand spine (looking at the insect from the 
front) has about midway of its length a small thorn -like 
projection at right angles to the spine. This little pro- 
jection is not as long as the remainder of the spine and 
presents a very remarkable appearance (fig. 2). I have 
never before met with anything of the sort, and on con- 
sulting Mr. H. St. J. K. Donisthorpe, f.e.s., who has given 
a great deal of attention to ants, he kindly informs me 
that he has never seen such a development of the spine 
though he has seen the spines of different lengths or blunted. 
He suggests that the cause of this abnormal growth was 
some injury to the larva or pupa. The specimen belongs 
to the race ruginodis of M. rubra. It was taken by me 
on Clare Island in June, 1911. 
Poyntzpass. 
1 
2 
