History of British Entomostraca. 327 
Description Body and tail not distinctly separated from each 
other ; composed of ten segments, first segment largest, last one, 
terminating in two short lobes, from which issue two long filaments, 
slightly serrated on their edges. At the junction of the fifth with 
the fourth articulation, the body is verymoveable, and the animal fre- 
quently turns up the posterior extremity upon the anterior, in the 
manner of the species of beetle called Staphylinus (Plate IX. Fig. 1.) 
Jurine has taken the trivial name of Staphylinus from this circum- 
stance, objecting to the name of minuius by which Muller desig- 
nates it, as he says it is possible we may find still smaller species. 
I have, however, retained the name which Muller gave it, as he is 
the first author who has given any lengthened description of it. The 
males are smaller than the females antennae, (Fig. 1, 2, a a) very 
short compared with those of preceding species. In female (Fig. 3) 
composed of nine articulations; in male (Fig. 4.) only of seven. Be- 
tween fourth and fifth articulation, in both sexes, we see a small 
lateral ring, of one short articulation and three or four short setae. In 
male both antennae have swelling and hinge-joint, the swelling exist- 
ing chiefly about the fifth articulation, all the five first, however, 
being of greater size than the corresponding ones in the female ; 
hinge-joint near the extremity. Antennules* (Fig. 5.) composed of 
two articulations : upon first articulation is placed a small shoot ter- 
minated by four setae, second articulation furnished with seven short 
spines on upper edge, and terminated by four longer ones. Jurine 
makes the antennules consist of six articulations, and his figure of these 
organs differs entirely from mine, which, after frequent and repeat- 
ed examinations, never varied in their appearance in the slightest. 
Mandible (Fig. 6.) in figure resembles very much the internal man- 
dible of the quadricornis, the " barbillon" springing from the centre, 
and consisting of three articulations, terminated by several setae. 
The lips in this species are easily to be seen, and are provided also 
with a " barbillon," which is a pretty large oval body (Fig. 7-) di- 
viding at extremity into four fingers of equal length, each furnished 
with three setae. Hands (Fig. 8.) of more simple organization than 
in the preceding species. They consist of three articulations, the 
last of which appears to be a very s fine hook, forming with the 
other two, an angle always directed forwards towards the mouth. 
These hooks appear to stop all molecules of food in their passage, 
and by their constant motions carry them to the mandibles. Feet 
(Fig. 9, 10,) much longer in proportion than in either of the preced- 
ing species, and differing in some respects from each other. 
* " Palpi" of Muller. 
