TATEM, ON NEW SPECIES OF MICROSCOPIC ANIMALS. 251 
methodical arrangement ; and although it is well known that 
Phryganea larve may, in the absence of their proper mate- 
rials, be forced to use others, I am still inclined to regard the 
presence of the layer of Conferva as a distinctive character ; 
for there are few other materials accessible to these aquatic 
larvee which possess the pliancy requisite for the arrangement 
adopted, and it appears to me to be in the highest degree im- 
probable that a larva which, under other circumstances, might 
have used other: materials, should have, out of this Conferva, 
constructed a case displaying such exquisite symmetry. 
One other supposition requires notice. It is possible that 
some of the larval forms of Hydroptila which have been de- 
scribed as forming a simple silky case might have afterwards 
adapted a layer of Conferva to its outer surface. An examina- 
tion of the central parts of the sides of the case before us, 
suggests that the silky case was constructed up to a certain size 
before any Conferva was applied to its outer surface. I have 
not been fortunate enough to see any specimen in so early a 
stage, but I can speak positively as to the contemporaneous 
addition of silk and Conferva in the more advanced stage. 
And from the analogy of the construction of the cases of other 
Phryganeide, it seems unlikely that the manufacture of the 
silky case should, to any considerable extent, precede the ad- 
dition of the Conferva to its outer surface ; and lam inclined 
to think that the few irregularly disposed filaments which 
may be observed at the centre of each side mark the period 
at which the contemporaneous addition of the two materials 
commenced. 
In conclusion, I beg to thankfully acknowledge my obliga- 
tion to Professor Westwood, to whom I described the speci- 
mens, for kindly aiding me from his large store of entomolo- 
gical knowledge. 
New Species of Microscopic ANIMALS. 
By T. G. Tate. 
I.—Chetonotus longicaudatus (mihi) is by no means un- 
common in some of the ponds in the neighbourhood of 
Reading, and is altogether an elegant creature in its propor- 
tions and movements, and, as seen in the cage, stealing 
through the various patches of decaying vegetable matter, 
on which it feeds, remarkably resembles some of the viverrine 
animals. The body is smooth, elongated, and but little 
