360 Johnson: Amphiprora paludosa. 
and was therefore much more saline than the upper portion 
which only contained -008 per cent: 
These results suggested a possible intimate connection 
between the salinity of the pit water and this uncommon 
diatom. 
A little later I took the opportunity to examine a similar 
water used for cooling purposes at Thornhill, and was agreeably 
surprised to find the same diatom again, and this time in much 
larger numbers; associated with it was WNitzschia Clausit 
Hantzsch, of which Van Heurck says, ‘ A de l’analogie avec les 
petites formes du N. obtusa,’ being 40 ». long by 4 p. broad, 
and has g-Io carinal dots and 32 striz in Io p. 
The effect of using this water for condensation raised the 
temperature to 96° F., thereby causing a considerable amount 
of concentration of the saline constituents of the water. The 
evaporation was so great that a large deposit of calcium car- 
bonate was formed at the bottom of the cooler where the 
diatoms were found. 
Since then I have found Amphiprora paludosa in similar 
situations both at Dinnington and Beighton, near Sheffield. 
The other diatom Nitzschia clausii, Figs. D and E, x 1000, 
I again found in large quantities almost pure in Aldwarke Dike, 
near Rotherham. This water has also been used for cooling 
purposes, and had at the time a temperature of 84° F. 
The presence in these small and obscure watercourses of 
such a strikingly characteristic diatom as Amphiprora paludosa 
in the West Riding seems to suggest that it is only in such 
places that the degree of salinity necessary for the development 
of this species can be artificially maintained. 
It will be interesting to notice how future West Riding 
localities bear out this suggestion, and if possible to determine 
the other factors affecting its distribution. 
It is also worthy of note that in West’s ‘ British Freshwater 
Alge,’ A. paludosa is said ‘ to be often found in fresh water, 
sometimes in great abundance in small ponds and ditches.’ 
20; 
In the Report of the Castle Museum Committee (Norwich) for 19:0, is 
a photographic illustration of a splendid specimen of the egg of a Great 
Auk, acquired by Mr. James Reeve, F.G.S., in 1910, and presented by him 
to the museum upon relinquishing his active duties as Curator. The egg 
is one of the finest known to collectors; it is mentioned by Hewitson in 
1856 as having been bought by Mr. H. F. Walter in 1850 from Dr. Pitman, 
who obtained it from Herr F. E. Brant, the dealer at Hamburg. It is 
evident from the illustration, which is actual size, that the marbling is 
very rich, and having been kept from the light, it is very little faded. 
The Report likewise contains an illustration of a Great Auk, from a restora- 
tion by Mr. Reeve. There is also a record of the year’s additions, lectures, 
etc. ; : 
Naturalist, 
