666 
considering the difficulty of distinguishing the fainter 
displays, is regarded as establishing the trustworthy 
character of the record by the general accordance be- 
tween the three independent observers. It appears, 
that, out of 215 favorable nights, 24 auroras were 
noted; and, if we may assume the same ratio to ap- 
ply to the cloudy nights, about 41 auroral displays 
occurred during the twelve months. 
These observations were undertaken to throw light 
upon the supposed connection between the number 
of solar spots and the frequency of auroras and of 
magnetic disturbances. They have now been con- 
tinued long enough to give interest to the following 
summary, compiled from the annual astronomical or- 
ders. It will be noted that there is a marked corre- 
spondence between the epochs of maximum and 
minimum auroras, and of maximum and minimum 
solar spots, as given by Prof. Fritz of Zurich; viz., — 
Epoch of maximum solar spots. . . . . « « 1870.6 
os minimum ‘* ie 1878.9 
a maximum ‘* Site ie 1882.4 
SCIENCE. 
[Vou. III., No. 69. 
The column headed ‘ Average number of sun-spots’ 
is derived from the observations of Prof. D. P. Todd, 
published by the U. S. signal-office. 
SUMMARY OF AURORAL RECORDS FOR FOURTEEN YEARS. 
RECENT PROCEEDINGS OF SCIENTIFIC SOCIETIES. 
Albany institute, 
May 13.—Dr. James Hall gave a description of 
some forms of newly discovered fossil sponges of the 
family of Dictyospongidae. Fossil sponges begin in 
the paleozoic rocks, and continue upwards through 
the coal-measures. The divisions of the fossil 
sponges are by fours : that is, some had four marked 
longitudinal lines or ridges; others, eight, and twelve, 
and sixteen. The most remarkable form was one 
with thirty-two radiating lines connected by concen- 
tric rings resembling a spider’s web. Of this there 
are only two specimens in the world, yet discovered ; 
and these arein the New-York state museum. Until 
within a few years the fossil sponges had been unde- 
termined, and many had regarded them as the remains 
of true vegetable forms of life. Europe, up to 1883, 
had produced but five species of fossil sponges of the 
family Dictyospongidae. From New-York state, Pro- 
fessor Hall has secured thirty-five species, thirty-one 
of which he has been the first to discover and to de- 
scribe. A notice of the family Dictyospongidae was 
read at the meeting of the American association for 
the advancement of science, in Montreal in 1882, and 
plates from the thirty-fifth Report of the New-York 
state museum of natural history were exhibited. The 
paper at present in press gives descriptions of the 
genera Cyathophycus, Dictyophyton (= Hydnoceras 
Conr. 1842), Ectenodictya, Lyriodictya, Thamnodic- 
tya, Phragmodictya, Cleodictya, Physospongia, and 
Uphantaenia, with numerous illustrations. 
Academy of natural sciences, Philadelphia, 
May 6. — Professor Joseph Leidy directed attention 
to some little tape-worms which had recently been sub- 
mitted to his examination. They were expelled, after 
Clear sky. Cloudy sky. I -2 
® Re) 
aie : > | Ae ; 
‘e Sa 2a 4 o Q 
Year.) are a af |e) |) mie ie 
oe Ho) 4 fe) o 
7 ex Z, A, ° Es, Hed oie 
1870 | ~ 184 50 150 41 99 - |11 mos. 
1871 | 211 60 154 44 104. = 
1872 | 234 60 132 34 94 2 
1873 | 214 54 151 38 92 = 
1874 | 190 18 175 17 35 = 
1875 | 189 14 176 13 27 = 
1876 | 195 9 il 8 17 & 
AST) LOL 7 174 6 13 2.6 | Began 
1878 | 185 2 180 2 4 2.2 | June, 
1879 | 204 9 161 7 16 2.0 | agitr 
1880 | 216 13 150 9 22 14.3 
1881 | 191 23 174 21 44 26.7 
1882 | 201 55 164 44 99 28.3 
1883 | 215 24 150 17 41 27.4 
the use of santonin, from a child of three years. The 
specimens, consisting of a dozen fragments, appear to 
be portions of three worms, which probably reached 
a length of from twelve to fifteen inches. Unfortu- 
nately the head is lost. The joints, or proglottides, 
are several times broader than long. The eggs occu- 
py a simple uterus, defined by the walls of the joints, 
and not divided into pouches diverging laterally from 
the main stem, as in most Taeniae. .A singular fea- 
ture of the worm is the interruption of the series of 
ripe joints, here and there, by one or more completely 
sterile ones. The generative apertures open in the 
usual way on the lateral margin of one side. The ma- 
ture eggs are spherical, measure 0.072 of a millimetre 
diameter, and contain fully developed, six-hooked 
embryos. While differing greatly from the ordi- 
nary tape-worms infesting man, they approximate 
nearly the description of Taenia flavopunctata, and 
probably pertain to this species. This has been 
but once previously observed, and was described in 
1858 by Dr. Weinland, from specimens in the muse- 
um of the Medical improvement society of Boston. 
These also were discharged by a child. It is probable 
that the worm is more common than would be sup- 
posed from the instances of its observation, and has 
perhaps escaped notice from its small size, and from 
the general ignorance of the distinction, not only of 
this, but of the ordinary species of tape-worms. —— 
Prof. J. T. Rothrock referred to the structure of the 
common violet, and remarked that he had observed 
that in the flower, the so-called path-finders, or lines 
of the petals leading to the ovaries, are much more 
conspicuous on the lower and side petals than on the ~ 
others, thus rendering them of most use to insects, — 
which are supposed to be guided by them to the ova- — 
ries. | qi 
