234 Miscellaneous. 
are directed backward, as in swimming animals. The dorsal and 
lumbar vertebre are shorter and more numerous; the lumbar ver- 
tebre bear no ribs; the tail represents only one fifth of the whole 
length of the body, whilst in the salamanders it equals nearly the 
half. 
The Salamandrella is very distinct from the reptiles of the Car- 
boniferous formation which have been described under the names of 
Labyrinthodonts, Ganocephali, and Microsaurians (such as Dendrer- 
peton, Hylerpeton, Hylonomus, Parabatrachus , Anthracherpeton, Uro- 
cordylus, Ceraterpeton, Sauropleura, Molgophis, &e.); but it differs 
less widely from Raniceps (Pelion) Lyelli trom Ohio. 
Now that the existence of true Batrachians in the Paleozoic rocks 
seems to be proved, probably no difficulty will be raised to placing 
Raniceps among those animals, as was proposed by Mr. Wyman in 
1858. It is probable that Raniceps had a naked skin, and that it 
possessed no entosternum, episternum, postorbital, or subsquamosal. 
Nevertheless it cannot belong to the same genus as the fossils of 
MM. Loustau and Delille; its vertebree are much more elongated, 
its frontals are less widened, the supraoccipital is thrown less back- 
wards, and its mandibles are more prolonged. Lastly, the animal 
from Ohio is three times as large. 
In 1844 Hermann von Meyer described, under the name oe 
Apateon pedestris, the impression of a reptile ‘found in the Carboni- 
ferous formation of Miunster-Appel. Notwithstanding the opinion of 
this talented paleontologist, I think that it belonged to an animal of 
the group of salamanders ; and if it were allowable to form a judg- 
ment from an impression so vague as that of Apateon, I should be 
inclined to believe this fossil to be identical with Salamandrella 
petrole.. Thus we should be acquainted with true Batrachians in 
the Palzozoic rocks of France, the United States, and Germany. 
The bituminous schists which contain Salamandrella petrolei also 
include remains of plants, numerous coprolites, and fishes (Paleo- 
niscus). M. Loustau has communicated to me a small crustacean 
derived from them, a series of well-ossified vertebre of a still 
unknown reptile, and a fragment of a humerus or femur agreeing in 
size with that of <Actinodon Frossardi, a curious Ganocephalous 
reptile, also collected in the bituminous schist, at Muse, not far from 
Igornay and Millery, which I brought before the Academy in 1866. 
To complete the list of Paleozoic reptiles found in France, I must 
remark that M. Paul Gervais has described a reptile from the 
Permian schists of Lodéve under the name of Aphelosaurus ; that 
learned naturalist has shown that it is very distinct from the 
Batrachians.— Comptes Rendus, February 15, 1875, p. 441. 
On the Motive Power of Diatoms. By Prof. J. Lemy. 
While the cause of motion remains unknown, some of the uses 
are obvious. The power is considerable, and enables these minute 
organisms, when mingled with mud, readily to extricate themselves 
and rise to the surface, where they may receive the influence of 
