WARD’S NATURAL SCIENCE BULLETIN. 
Dictyophyton. 
During the past season a nest 
containing several hundred fine 
specimens of this interesting fossil 
was found in Steuben county, N. 
Y. , and we were fortunate enough 
to secure the whole “find.” Mr. 
Conrad first described the fossil, 
and gave to it the generic name of 
Hydnoceras, with the belief that it 
was a Cephalopod, and Prof. Hall, 
in the 16th Annual Report on the 
State Cabinet of Natural History 
of New York, attempts to show that 
it is a marine plant, and considers it one of the 
“Algae of a peculiar form and mode of growth.” 
and proposes the name Dictyophyton , which has 
been universally adopted. And now (see American 
Journal of Science for July and August) we find 
Prof. Whitfield and Dr. Dawson claiming, and 
apparently with good reason, that the true place 
for Dictyophyton (and UphantEenia of Yanuxem) 
is with the sponges, and that it is a near relative 
of the beautiful Euplectella of the present day, 
found at the Phillipirie Isles. Prof. Whitfield 
says, “ These bodies ( Dictyophyton. s) are more or 
less elongated tubes, straight or curved, cylin- 
drical or angular, nodose or annnlated, and that 
they have been composed of a thin film or pel- 
licle of network, made up of longitudinal and 
horizontal threads which cross each other at 
right angles, thereby cutting the surface of the 
fossil into rectangular spaces, often ivith finer 
threads between the coarser ones. When the 
specimens, which are casts or impressions in 
sandstone, are carefully examined, it is found 
that these threads are not interwoven with each 
other like basket work, or like the fibres of cloth, 
nor do they unite with each other as do vegetable 
substances; but one set appears to pass on the 
outside, and the other on the inside of the body. 
The threads composing the net-work vary in 
strength, and are in regular sets in both direc- 
tions, while the entire thickness of the film or 
substance of the body has been verv inconsid- 
erable.” * * * 
“In examining the structure of Euplectella it 
is found to be composed of longitudinal and 
horizontal bands similar to those above described, 
with the additional feature of sets of fibres pass- 
ing in each direction obliquely across or between 
the longitudinal and horizontal sets, but not 
interwoven with them; so that the longitudinal 
series forms external ribs extending the length of 
the sponge, and the horizontal series inside ribs 
or bands, and they appear as if cemented to each 
other at their crossings. The oblique threads, 
besides strengthening the structure, cut the an 
gles of the quadrangular meshes formed by the 
two principal sets of fibres, and give to them the 
appearance of circular openings, making the 
structure much more complicated than in Dicty- 
ophyton. The addition of oblique fibres in Euplec- 
tella is the most noticeable difference between 
the two forms; but if placed horizontally and 
longitudinally between the primary sets they 
would produce precisely the structure seen in 
Dictyophyton. ” 
Dr. Dawson remarks of a specimen of Uphan- 
taenia sent him by Prof. Whitfield: “The spic- 
ules of the transverse bands cross those of the 
longitudinal ones without any organic connec- 
tion. Among the long spicules of the bands can 
be seen multitudes of very minute and appar- 
ently short spicules confusedly disposed, and these 
abound also in the dark colored areoles. On the 
whole the structures are not identical with those 
of anjr plant known to me, and rather resemble 
those of silicious sponges of the genus Euplec- 
tella.'’'' 
The Dictyophyton is very remarkable in its 
mode of occurrence. Although by no means a 
common fossil, when found at all it seems to be 
found in great numbers. The friend from whom 
we obtained our specimens helped to dig them 
out, and says they were all found in a space only 
eight or ten feet in diameter and four or five feet 
in depth, and some specimens of the rock we 
have show how very thickly they were bedded 
together. W e believe, also, that most of the speci- 
mens previously obtained were found in a pocket 
similar to this one. 
PHENOMENAL GEOLOGY 
We have grouped together a collection of 75 speci- 
mens which illustrate the different phenomena of 
Dynamical and Structural Geology, such as faults, 
veins, metamorphism, varieties in structure and 
texture, etc., including the wood models men- 
tioned below. This is one of the first collections 
a teacher in Geology should have. 
RELIEF MAPS 
of especially interesting geological regions, such 
as Vesuvius, Etna, Mt. Blanc, Isle of Palma, 
Auvergne, Colorado Canon, Henry Mts., &c. 
These maps are exact models of the x-egions rep- 
resented, made to a definite scale, thus showing 
at a glance all the topographical features in their 
correct proportions. Colored as they are geolog- 
ically, they not only show the relations of the 
different formations to each other, but illustrate 
the structure as well, and show the entire depend- 
ence of the topography on them, thus proving 
invaluable aids in the study of physical geogra- 
phy as well as geology, and at the same time very 
ornamental and attractive object's in a museum. 
The features of structure and erosion are still 
more graphically illustrated by means of a series 
of stereograms, which show the country as it 
would be folded and faulted without erosion. 
GEOLOGICAL MODELS. 
We also have in this depart ment a series of six 
dissecting models in wood, wdiich show more 
clearly than is possible in diagrams the effects of 
erosion, veins, faults, outcrops, ets. Price of set, 
in handsome case, and accompanied with printed 
explanatory catalogue, 
GEOLOGICAL CHARTS AND PIC- 
TURES. 
We have geological charts of all kinds. We 
would call particular attention to the CHART OF GEO- 
LOGICAL TIME, prepared by Mr. Howell for the 
U. S. Geological Survey In this Chart the strata 
of the different States of the Union, Canada and 
Europe, are correlated, and approximate thick- 
nesses given, the whole so arranged as to show at 
a glance to what Epoch, Period, Age and Era 
they belong. Size, 8x4 ft. Price, mounted with 
black walnut roller, $2. 
Also, a series of sixteen Lithographic Pictures 
of ideal geological landscapes, by Dr. Unger. 
Size 19 x 24 inches; price of set, nicely boxed and 
framed, $70. 
Restoration of Extinct Animals, by B. 
Waterhouse Hawkins. Size 2 ft. 6 in. x 8 ft. 3 in. 
Price of this famous set of six pictures, nicely 
framed, $60. 
CHARACTERISTIC FOSSILS. 
These are careful hand-made, water-color draw- 
ings of a celebrated series, by the late Edward 
Forbes, now in the Museum of Practical Geology, 
London. The pictures are all on first quality 
drawing paper, of uniform size (27 x 36), and the 
price of each is $8. From the number we have 
made a selection of ten pictures to constitute a 
series by itself, and this series comprises the 
following: One Graptolites, two Zoantharia, one 
Echinodermata, four Mollusca, two Crustacea. 
Price of this special series unframed, $75; 
framed, $110. 
GOLD MEDALS. 
The Gold Medals mentioned in our lasUBuLLE- 
tin, Avhich were awarded at the late International 
Exposition at Melbourne, Australia, have just 
been received, and the accompanying cuts exhibit 
the two sides. These two “Highest Awards” 
are for “Systematic Collections of Minerals and 
Rocks,” and for “Natural History Collections 
Intended for Higher Instruction and Scientific 
Research.” 
Precious Opal. 
Since the time Pliny accurately described his 
opalus, to the present day, this handsome mineral 
has been esteemed a gem, though not always 
assigned the same rank; for fashion, in its capri- 
cious vagaries, displaces and reinstates it in favor 
at irregular intervals. Its innate beauly, so hap- 
pily characterized in the lines, 
“ Milky opals that g-leam and shine 
Like sullen tires through a pallid mist,” 
coupled with the fact that it is perhaps the only 
stone really defying imitation, has enabled it to 
eventually hold its own. The high rank awarded 
it in ancient times was undoubtedly largely due 
to the comparative ease with which it could be 
worked, and also to the fact that unlike all other 
precious stones much of its beauty was revealed 
and available without any labor. The strange 
popular belief of modern days that opal is an 
unlucky stone to the wearer, appears to be di- 
rectly traceable to Sir Walter Scott’s romance of 
“Anne of Geierstein.” In its usual occurrence 
in seams or veins in porphyry and igneous rocks, 
it is plainly an infiltration of gelatinous silica 
(silica in the colloid state), often mixed with con- 
siderable crystalloid silica, and retaining more or 
less of the originally combined water. Indeed, 
precious opal proper seems, as a rule, to contain 
more water than the other varieties. Until within 
the past few years the greater part of the material 
for commerce has been of Hungarian and Mexi- 
can origin, but a new source of supply has been 
discovered in Queensland. In the variety from 
this locality, which may in some respects be con- 
sidered unique, the usual fiery reflections are 
displaced partly, or even entirely, by the most 
splendent metallic hues — greens and blues of 
every conceivable shade — the individual colors 
in some instances being arranged in more or less 
distinctly defined bands or zones, or again imper- 
ceptibly melting into each other and vying with 
the plumage of humming birds in magnificence. 
Clearly the old descriptions will need enlarging 
to cover this latest addition to the numerous 
forms of silica. F. W. S. 
We have fine specimens of Dictyophyton tuber- 
osum and D. nodosum from 50 cts. to 13.00 
