117 
of a new Irish Crustaceous A nimal. 
canal passes upwards and backwards towards the hollow base of 
the posterior dorsal spine ; it then curves downwards, accompanied 
by the aorta, within the descending dorsal lamina, till it arrives at 
the inferior embouchure, when it begins to pass backwards within 
the joints of the tail. This tail is composed of six or seven de- 
pressed joints, of which four present themselves externally, the first 
from behind two transverse spines or processes ; its breadth about 
equals its length, and furnished posteriorly at each side with a 
little tooth directed slightly outwards. The two succeeding joints 
are precisely similar, towards the tips however slightly diminished 
in breadth ; the terminal joint forms a crescent, or is widely 
forked, each bifurcation passing outwards, furnishing a tooth ex- 
teriorly, and three plumed spines internally, and then bending 
suddenly backwards, gradually diminishing in breadth, and ter- 
minating somewhat acuminate, the tips curving upwards. 
In colour the animal is a brilliant brownish green, the green 
hue predominating about the eyes and front ; the brown inferiorly 
and posteriorly, and assuming a somewhat reddish tint about the 
mouth, intestinal canal, and processes from the caudal joints. The 
base of the last joint of the tail is dashed with red, and a con- 
colorous macula is in each of the furcse about the position of the 
spines. The legs, antennae, and processes, are hyaline. 
Taken by Mr. R. Patterson, V. P. Belfast Nat. Hist. Soc., in 
the same place as the Anomalocera P attcrsonii (Larne Lough, 
county Antrim), on the 9th of May. 
Plate XII. fig. 1. Represents the animal as seen from above, and very highly 
magnified. 
2. Seen obliquely from beneath, to show the edge of the 
buckler, and relative positions of the interior parts. 
3. The greater part of one side removed to show the positions 
of the parts of the mouth and of the legs. 
4. Part of this further enlarged, to show more clearly the 
mouth and appendages. 
5. Part of the head, the eye being removed to exhibit the ori- 
gins of the antennae, and the connection of the inferior 
to the second series of oral appendages. 
6. 6'. The last joint of the inferior antenna seen in two posi- 
tions. 
7. Tip of the same antenna. 
8. One of the second series of oral appendages. 8*. Tip of 
the superior process of the same. 
9. The articulated appendage at the tip of the larger division 
of the legs showing tire mode of attachment of the six 
hairs. 
It). One of tire spines of tire last joint of the tail, to show the 
manner in which it is plumed. 
K 2 
