200 Prof. C. Chilton on the Freshwater Isopods 
which is nearest to France. When the distribution of the 
Diplopoda of these islands is better known, we may find that 
such an occurrence has a special biological significance. 
The wood where our specimens were captured is situated 
along the slopes and summit of the Jow chalk-hills which 
form part of the Wye Downs, running roughly north and 
south about a mile from Wye itself, and rising on the south 
from the Selbornian tract below, and on the west from the 
Chalk valley of the Great Stour, to a little over 500 feet above 
seaglevel in some places. In the area of the wood where we 
took P. germanicum, some three-quarters of a mile E.N.E. 
from the town, the altitude is only some 400 feet, or 200 to 
300 feet above Wye itself. In this portion of the wood 
hazel, beech, and coniferous trees are well represented, while 
the ground is often covered with grass and low-growing 
plants, among which there is a considerable quantity of fallen 
leaves and other plant débris in autumn. It is among the 
fallen leaves in this situation that we have taken Polyzonium. 
As Mr. Daffield pointed out to me on one of our visits to this 
hunting-ground, there is quite a striking superficial resem- 
blance between this new millipede with its yellow to 
brownish colouring and the fallen bud-cases of the beech to 
be found at Juniper Wood in the vegetable débris in which, 
as already stated, the animal itself occurs. 
REFERENCES. 
(1) Latzet, Roprert. ‘ Die Myriopoden der ésterreichisch-ungarischen 
Monarchie,’ i. (1884). 
(2) Pocock, R.I. Article “ Millipede” in Encye, Brit. 11th edit. 1911, 
xviii. pp. 468-475 et seq. 
(3) Sunciarr, F.G. “ Myriapods” in ‘The Cambridge Natural History,’ 
1910, vol. v. pp. 27-80. 
(4) Vernorrr, K. W. “Ueber Diplopoden aus Bosnien, Herzogowina 
und Dalmatien—V. Glomeride & Polyzoniide (Schluss).” 
Archiy fiir Naturgeschichte, Jahrg. 64, 1898, pp. 161 e¢ seg., 
pl. vii. ; 
(5) ‘Die Diplopoden Deutschlands,’ 1911-14. 
Wye College, Kent, 
19th December, 1919. 
XXVIIL.—WNote on the Freshwater Isopods known as Asellus 
aquaticus. By Cuas. Curitron, M.A., D.Sc., M.B., O.M., 
LL.D., C.M.Z.S., F.L.S., Professor of Biology, Canterbury 
College, New Zealand. 
TE little freshwater Isopods which are common in many 
streams of different parts of Hurope have hitherto always 
been known under the name of Asellus aquaticus, and, 
