382 The American Naturalist. [April, 
An Ottrelite Bearing Conglomerate in Vermont.—It is not 
uncommon to find ottrelite forming 25% of the schistose groundmass 
of the conglomerate? at the base of the Lower Cambrian, near Rut- 
land, Vermont. The same mineral occurs along shear planes in a 
blue quartzite and constitutes 40% of a massive bed of the conglom- 
erate. In the last named rock the ottrelite is in rudely circular areas, 
lying in a dark colored quartz. The areas consist usually of radiating 
plates of the mineral, disposed in a single plane. Its commonest 
inclusions are quartz and feldspar, while sericite often forms the cen- 
ters of the radiating bundles. In the latter case the ottrelite is 
oriented in parallel position with the mica. Other inclusions within 
the ottrelite besides those above mentioned are crystals of zircon and 
rutile, flakes of graphite and plates of ilmenite. In other cases the 
ottrelite is in plates including large areas of the groundmass of the 
rock, which is a granulated mixture of quartz and albite (?) in about 
equal proportions, a large quantity of sericite, and some biotite. In 
this groundmass associated with rutile are crystals and plates of ana- 
tase. No traces of its original clastic structure remain in the rock, 
though its conglomeratic character is beyond dispute. 
Lithophysz in the Rocche-Rosse.—In parts of the Rocche- 
Rosse lava stream of Monte Pelato, Lipari, are spherulites with litho- 
physal characteristics. In some specimens examined by Cole and 
Butler’ the spherulitic growth originated about the walls of steam 
vesicles, and progressed outward into the rock; in other cases they 
grew inward until they have completely filled the space that was for- 
merly vacant. The importance of the paper lies in the fact that it 
acknowledges the correctness of many of Idding’s views with respect 
to the formation of lithophysz, and contradicts the view that regards 
all hollow lithophysz as the result of the decomposition of spherulites. 
The Composition of the Dune Sands of the Netherlands. 
—A very elaborate paper by Retgers® on the constitution of sand 
composing the dunes on the west coast of Holland at Sheveningen, 
near the Hague, contains a large amount of information concerning 
the character of sands and the method of determining the nature of 
their constituents. The author carefully fractioned large quantities o of 
the dune sand by the ordinary methods of fractional precipitation in 
SC. L. Whittle, Amer. Jour. Sci., Oct., 1892, p. 270. 
"Quart. Jour. Geol. Soc., xlviii, 1892, p. 438. 
"Recueil des Travaux Chimiques des Pays-Bas., xi, 1892, p. 169. 
