482 The American Naturalist. [May, 
Finally, the Miocene sands which form the valleys between the spurs 
of the Acouquija (Tucuman and Catamarca) have furnished M. Manuel 
. B. Zavaleta with remains of fossil mammals indicating a fauna almost 
entirely new, and which is badly represented in the formations of the 
same epoch hitherto explored. 
These fossils will be described in the next number of the Revista 
Argentina, as well as the new type of Ungulates named by M. Ame- 
ghino Wotohippus toxodontoides.— Revue Scientifique. 
_ Water-Marks on Paleozoic Rocks.—In the Quar. Jour. Geol. 
Soc., Nov., 1890, Sir Wm. Dawson has figured and described some 
peculiar markings of Paleozoic rocks. Bilobites, which have been 
regarded by Saporta, Delgado, and others as true algæ, are, so far as 
American examples are concerned, undoubtedly the tracks of a marine 
animal, probably crustacean. Scolithus, originally placed with fucoids, 
represents burrows of worms with castings at their entrances. Sabel- 
larites is a name the author proposes for certain elongated tubes com- 
posed of grains of sand and calcareous organic fragments associated 
with carbonaceous flocculent matter, indicating a horny sheath. They 
are formed of the phosphatic dejections of animals subsisting on Lin- 
gulz, Trilobites, Hyolithes, and other creatures having coverings of 
calcium-phosphate. Certain trunk-like forms in the Potsdam Sand- 
stone are now shown to be concretions, the nucleus of which must 
have been a Chorda-like alga. , 
In many cases species of fossil plants have founded on rill-marks, 
notably the genera Dendrophycus, Delesserites, and Vexillum. 
The Mutual Relations of Land-Elevation and Ice- 
Accumulation during the Quaternary Period are described 
by Professor Joseph LeConte as follows : i Ji 
“It is generally agreed that the Quaternary was characterized es 
remarkable oscillations of land lével, and corresponding oscillations g 
climate and of ice-accumulation. But the most opposite views are 
held regarding the time-relations of these two sets of phen i 
Some hold that the land-elevation was coincident with the cold ap 
the ice-accumulation, and was at least one of its causes ; and that E 
moderation of temperature and removal of the ice was coincident e 
the depression, and was its effect. Others take exactly the o 
view. I believe thatthe two extreme views may. be reconcley oo 
all facts satisfactorily explained, by supposing (1) that the corm 
elevation which commenced in the Pliocene culminated in the ae 
