562 Proceedings of Scientific Societies. [May, 1884 
to be presented; there was also read a paper by Samuel Knee 
land, M.D., entitled, A visit to the crater of Vesuvius at night in 
April, 1882. 
PHILADELPHIA ACADEMY OF NATURAL SCIENCES, Dec. 20.—Dr. 
A. J. Parker called attention to a previously unnoticed mode of 
reproduction in Avmphileptas fasciola. One end broke up into 
ameceboid particles, while the remainder, with its cilia, was active. 
The creature afterwards resumed its original form. The Rev, Dr. 
McCook spoke of the occurrence of Formica rufa in Dakota. In 
the center of the mounds was a mass of small twigs, forming à 
ball some eight inches in diameter, and galleries run downward 
from this for four or more feet. As the material of the nests 1$ 
largely composed of vegetable fragments, prairie fires burn them 
out, forming large cavities. ae 
January 10, 1884.—A paper by Miss Foulke, describing the 
reproduction of Clathrulina elegans, was read. Professor Lewis 
exhibited a mass of cast-iron which contained crystals of graphite, 
which again held particles of cast iron. The mass contain 
pieces of unaltered anthracite. The presence of such za E 
coal, unconsumed through lack of oxygen, was conside! b 
illustrate the way in which carbon may exist in meteorites 
chalcopyrite in trap. Dr. Sharp stated that he had ona = 
the presence of so-called retinal cells in the mantle of many es 
libranchiata, including Mya and Ostrea. The structure T pA 
same as that of the primitive eyes of Sølen ensis per 
scribed. The relation between these eyes and those gi ; 
could scarcely be traced. At the previous meeting, Hills ee 
called attention to specimens of tin ore from the Black Hill's, 
stated that he had been informed that a large quantity 
existed, the lif- 
Jan. 16.—Dr. Leidy, in the course of remarks upon oted the 
forms thrown up at Atlantic City by recent storms, 2 ae 
presence of the holothurian Caudina arenata. e cd Jersey 
3 eil- 
is i ound. Professor n 
coast. Examples six inches long were fi rte ‘Atlantic coast 
stated that the Vicksburg beds were, as determined by Olt 
probably of the same age as the Mayence 
mantellii was characteristic of both and of Oligoc 
ally. The strata immediately beneath the Vicks e 
strata which are the equivalent of the Ca/caire grenn d 
and contains Zeuglodon remains. In the Gra : 
far south of Alabama, Mississippi and Louisiana, “gi o 
invertebrate fossils had been seen. The Jackson Of sg by H 
extend farther up in Mississippi than had been su f eggs of | 
gard. Remarks upon the abundance of chaplets belief 
gur during the winter led Dr. Leidy to state his 
are laid in winter and cast up by the spring storms. 
