166 
NATURE 
[JUNE 12, 1902 
lamellze flat or plicate, and the filaments all of one kind or with 
enlarged principal filaments at intervals. 
Avicula argentea proved to be a form of supreme interest, in 
that both ciliated discs and organic interfilamentar junctions are 
present. 
Anomia aculeata is of no less interest, since it differs from the 
other species of Anomia examined, and resembles the rare 
Dimya, in that the gill filaments are not reflected. 
The gills of Vesicomya and Euciroa, which were said by Dall 
to exhibit close resemblances with those of the Protobranchia, 
prove to be of the reticulate type. 
The forms included by Pelseneer in his order Septibranchia 
are, at least so far as can be judged by their branchial organs, 
degenerate molluscs of the Lyonsiella type, and the suppression 
of the Septibranchia as a distinct order is advocated. 
Entomological Society, May 7.—The Rev. Canon 
Fowler, president, in the chair,—Mr. H. W. Shepheard-Walwyn 
exhibited a gynandromorphous specimen of Azthocarés carda- 
mines, taken near Winchester in 1899. The left side was that 
ofa normal ¢, the right that of a normal 9, with the exception 
of a splash of orange pigment on the underside of the primary. 
—Mr. H. Goss exhibited two ¢ specimens of Saturnia carpint 
from Essex, bred on whitethorn, and three 3 3g of the same 
species caught in Surrey by the aid of bred (virgins) 9 2. He 
remarked that as a rule bred specimens were smaller than wild, 
but the bred Essex specimens were much larger than those 
captured in Surrey. The Essex specimens were light in colour, 
while the Surrey specimens were not only much smaller in size, 
but very dark, probably because their larvae had fed upon Erica 
or Calluna.—Colonel C. Swinhoe announced the emergence of 
Cossus lignipferda in the Zoological Society’s Gardens from a 
pupa received in a piece of wood from South Africa, and said 
that it was remarkable that the species should have been intro- 
duced there and then brought back to Great Britain. —Prof. 
E. B. Poulton exhibited two Euploeinze captured in Fiji by 
Prof. Gilson, and presented by him to the Hope Department. 
The species, which belonged to the different genera Nipara 
and Deragena, bore the closest superficial resemblance to each 
other, affording an interesting example of Miillerian or 
synaposematic likeness.—Prof. Poulton also exhibited several 
specimens of Swmerinthus fopult which had been exposed 
during the pupal stage to the intense heat of July, 1900. In 
consequence of this *‘ forcing,’ the moths emerged towards the 
end of that month, and were markedly different in colour from 
the normal, being much paler in tint with less distinct markings, 
and the red of the hind wings of a very different shade.—The 
Rey. A. E, Eaton exhibited drawings illustrating the wing of 
Pampterinus latipennis, Etn. MS., a remarkable dipterous fly 
of the family Psychodidze, from New Guinea, in the collection 
of the Hungarian National Museum, Budapest.—Prof. L. C. 
Miall, F.R.S., contributed a paper on a new Cricket of aquatic 
habits found in Fiji by Prof. Gustave Gilson, Dr. T. A. 
Chapman a paper on asymmetry in the males of Flemarine 
and other Sphinges, and Mr. E. Meyrick a paper on Lepi- 
doptera from the Chatham Islands. 
Geological Society, May 14.—Prof. Charles Lapworth, 
F.R.S., president, in the chair.—Pliocene glacio-fluviatile con- 
glomerates in Subalpine France and Switzerland, by Mr. Charles 
S. Du Riche Preller. In the present paper the author describes a 
number of further deposits of typical Deckenschotter conglom- 
erate recently examined in the Aare and Rhine valleys, near the 
confluence of those rivers, and shows that these, in conjunction 
with the Deckenschotter deposits of the Zurich district, indicate 
the almost unbroken outline of a Subalpine Deckenschotter cone, 
which extended from the base of the Alps in a north-westerly 
direction over a distance of about 25 miles, and was formed 
by the waters of the retreating Rhine (western) glacier and its 
affluents on a Molasse plateau, the upper and lower ends of 
which were at the contours of 900 metres and 500 metres 
respectively. He further describes a series of Deckenschotter 
deposits examined in the Rhone valley between Lausanne and 
Lyons, including the extensive plateau of the Dombes, east and 
north of Lyons, composed of marine marl overlain by the 
characteristic conglomérat ferrugineux, which some French 
geologists still regard as pre-Glacial and others as Quaternary, 
but which is typical Deckenschotter, and in the full acceptation 
of the term an alluvion des plateaux. The deposits thus 
described afford proof of the existence, in Upper Pliocene 
NO. 1702, VOL. 66] 
| 
times, of an extensive alluvial cone about 100 miles in length, 
which reached from Lausanne (probably even from the base of 
the Alps) to Lyons, and was formed by the waters of the 
retreating Rhone and Arve glaciers on a Molasse-and-marl 
plateau, the altitude of which above sea-level was 800 metres 
near Lausanne and 300 metres near Lyons. From this con- 
current evidence in northern Switzerland and in the Rhone 
valley, the author is led to conclude that at the time of the 
deposition of those alluvial cones, the principal Subalpine 
valleys and lake-basins could not as yet have. existed in their 
present form or depth, and must have been from 100 to 200 
and 400 metres higher ; and that the Subalpine valleys were 
eroded to their present depth in the course of the inter-Glacial 
period—now recognised to have been of very long duration— 
between the Pliocene and the Middle Pleistocene (or maximum) 
glaciations, and that the Subalpine lake-basins were formed in the 
same period by the contemporaneous action of fluviatile erosion 
and of a zonal settling along the base of the Alps after these had 
been raised by horizontal pressure.—Overthrusts and other 
disturbances in the Braysdown Colliery (Somerset), and the 
bearing of these phenomena upon the effects of overthrust-faults 
in the Somerset coalfield in general, by Mr. F. A. Steart. This 
coalfield, although covered by comparatively undisturbed 
Secondary rocks, is in part the most disturbed and contorted of 
those known and worked in the United Kingdom. The 
“*Radstock Seams” of the Upper Coal-measures at Radstock 
are traversed by a huge ‘‘overlap fault,” which thrusts them 
forward for a great distance ; this runs nearly east and west, and 
has parallel to it two smaller overthrusts. In one of them the 
coal at first dips towards the thrust, then it thickens from 2 to 6 
or 8 feet, next it becomes inverted, and eventually regains its 
former character. The continuity of the coal has been proved 
in the case of three of the coal-veins. As there is practically 
the same sequence of strata on both sides of the fault, it is con- 
cluded that the ‘‘overthrusts” did not take place until all the 
coal-seams of the Radstock series had been deposited. 
Royal Microscopical Society, May 21.—Dr. Hy. Wood- 
ward, F.R.S., president, in the chair.—Mr. T. W. Ersser 
brought for exhibition a new acetylene illuminator for the 
lantern which he said would give a light of 300 candle power 
for three hours at a cost of ninepence.—Mr. D. J. Scourfield 
gave an exhibition of freshwater Entomostraca. He confined 
himself to the Cladocera and to the illustration of their various 
habits of life and powers of movement, ranging from the free- 
swimming forms found in lakes to those which simply crawled 
in or on the mud. Most of the living specimens were shown in 
live boxes, but one specimen was attached to a pin by means of 
a small drop of sealing wax varnish, which permitted the 
creature to carry on all its movements without getting out of the 
field of view. A number of living and mounted specimens were 
exhibited under microscopes. 
CAMBRIDGE. 
Philosophical Society, May 19.—Prof. Macalister, 
president, in the chair.—Some observations on protandry and 
senescence in Flabellum, by Mr. J. Stanley Gardiner.—A 
note on the dispersive power of running water on skeletons : 
with particular reference to the skeletal remains of Pithecan- 
thropus erectus, by Mr. W. L. H. Duckworth. This com- 
munication consisted in an account of the distribution of the 
bones of the skeleton of a horse along the bed of a mountain 
stream in North Wales. It was observed that the distance over 
which distribution had occurred was at least one hundred and 
fifty-three feet. This observation was applied to the case of the 
fossil bones found in a river bank in Java and described by 
their discoverer as those of an animal more closely allied to man 
than is any known ape and called Pithecanthropus erectus. 
One objection to this description rests on the fact that the two 
bones on which our knowledge of that animal is based were 
separated by a distance of nearly forty-nine feet, though on the 
same level. The present observation goes to show that this 
objection is not valid, inasmuch as the larger bones here 
mentioned were distributed over a considerably greater distance 
than forty-nine feet, by a stream of small dimensions.—The 
coral reefs of Zanzibar, by Mr. C. Crossland. The paper shows 
that the fringing reef which extends along the whole eastern or 
ocean side of Zanzibar Island is not due to recent growth, but 
is the result of the eroding action of the sea upon the margin of 
the mass of elevated coral limestone which forms this side of 
