40 Scientific Proceedings, Royal Dublin Society. 
a little web spread about, against a bar of which it finally attached 
itself by the middle of the foot, swung round and round head over 
heels with great rapidity, a most amusing sight; then a sudden 
dart of lightning speed, and it was gone. I found it again, but it 
had grown wild and restless, and we soon bid adieu forever. Since 
then I have met with numbers of them from two different locali- 
ties; they bear confinement well, and increased rapidly in a large 
pan into which I had thrown the water containing them. The re- 
presentation of the species in the Monograph is so truthful both in 
form and colouring that it leaves me little to say. The stomach 
always appeared to be distinctly two-chambered, the lower chamber 
being about two-thirds the size of the one above it, the line of 
division marked by a slight constriction, and also by the different 
condition of the contents. The bright red organ mostly present was 
even larger than given in the figure alluded to, and unsymmetric 
in shape, but examples also occurred in which it was absent; and 
in the latter case the whole body was invariably studded over with 
globules, some of which were tinged with yellow, and had an oily 
appearance. The coronal disc, though always open, was rarely ex- 
panded to the plate-like flatness represented in the above figure. 
I have seen it suddenly close over an atom within the circle to 
prevent itsescape. The margin of the disc invariably swept down 
in an open V-shaped curve to a point upon the breast. 
Both the under and upper surface of the mastax were deeply 
tinged with purple, looking like two transverse purple plates, upon 
the latter of which rested the large purple eye. Occasionally I 
detected a low dorsal ridge, running from under the dorsal antenna 
to the base of the foot. The ovary was always of large size, and 
remarkably clear; the contractile vessel was well defined. 
Habitat.—A bog, a drain, Co. Wexford. 
Microcodon (?) robustus, sp. nov. 
(Pl. III. fig. 2.] 
Sp. Ch.—Body smooth, cylindric, stout; corona of the same 
diameter as the trunk; foot almost as long as the body; toe single, 
stout, and acutely pointed. 
This species most probably belongs to the family Microcodida, 
Se 
