pieces several feet in diameter. These are cemented together by finer
portions of the same substances, among which have been deposited zeo-
lites, carbonates, opal and other secondary minerals. Some beds of
this tuff are so filled with large fragments of basalt, tephrite, etc., that
the rock composing it has been called the "Brocken Tuff." It is to
the study of the fragments in this tuff that Graber's paper is devoted.

The basalts and tephrites constitute sheets and lava streams that are
interstratified with the tuffs and sediments. Among the former rocks
are noticed feldspathic, leucitic and nephelinic varieties, besides in
several places magma-basalts. In addition to sheet basalts, dykes and

The

chimneys of this rock have also been observed.
The rocks in all their forms are normal in their development.
author regards contact action around the chimneys as the safest crite-
rion by which to distinguish these forms from denuded sheets and
flows. The tephrites comprise hauyn-tephrites, in which hornblende
and aegerine are present, nepheline-tephrite, including trachytic and
andesitic varieties, and leucite-tephrite composed of phenocrysts of
augite, plagioclase and grains of magnetite in a groundmass of these
same components, and leucite, biotite and nepheline.

The augite consists of two generations of magnetite and augite in a
glassy base. Its analysis gave:

SiO, TiO, PO, Al,O, Fe,O, FeO CaO MgO K2O Na2O H2O Moisture Total 3.35 1.43 1.54 11.46 11.98 2.26 7.76 11.69 .99 3.88 2.41 .59 99.34

The feldspathic basalt and the andesitic tephrite are the only rocks
that seem to have affected the sediments with which they are in con-
tact. Quartzites are changed to aggregates of quartz grains in a glass
matrix, where the action is not extremely severe, and to an aggregate
of interlocking quartz grains where it has been intense. The article
closes with an account of the detailed results of analysis of ten speci-
mens of the volcanic rocks.

Graber's article is devoted principally to a description of the frag-
ments found in the Brocken-tuff. These are all tephritic rocks, among
which andesitic, leucitic and phonolitic types are recognized. The
characteristics of the components of all these types are portrayed in
great detail, especial care being given to the descriptions of the augite
and the plagioclase. The phonolitic tephrite is characterized by the
presence of nosean, which is in irregular grains. In the andesitic teph-
rite, which is the most basic variety, the porphyritic augite has an ex-
tinction angle AC of 58°-62°, in the leucitic type its extinction is

52°-56° and in the phonolitic type, the most acid variety, it is 50°53°. In each of the types labradorite and sometimes oligoclase phenocrysts are common, but the feldspar of the groundmass differs in character in the different types. In the andesitic type it is oligoclase, in the leucite variety andesine, and in the phonolitic type sanidine.

A Nepheline-Syenite Bowlder from Ohio.-Miss Bascom' has found in the drift near Columbus, Ohio, a bowlder which consists of nepheline-syenite porphyry. The rock is composed of large phenocrysts of oligoclase and smaller ones of nepheline, augite, hornblende and olivine in a groundmass composed of plagioclase and orthoclase laths, hornblende, biotite, augite and magnetite in a feldspathic matrix.

Crystalline Rocks of New Jersey.-In a report on the Archean Highlands of New Jersey, Westgate' states that the northern half of Jenny Jump Mt., Warren Co., consists mainly of gneisses with a small area of crystalline limestone, diorites, gneisses, etc. The gneisses are granitoid biotite-hornblende varieties, biotite-gneisses and hornblende-pyroxene gneisses. In the first named variety the prevailing feldspars are microcline and microperthite, and in the pyroxene gneisses plagioclase and orthoclase. The gneisses are cut by pegmatite dykes,

amphibolites and diabases.

Associated with the white crystalline limestones are fibrolite and biotite gneisses, hornblendic gneiss, amphibolites, gabbros, norites and diorites, most of the latter of which show evidence of an eruptive origin. Another type of rock often found associated with the limestones is a quartz-pyroxene aggregate, in which the pyroxene is a green or white monoclinic augite. The limestone, the fibrolite and biotite gneisses and the quartz-pyroxene rock are thought to be metamorphosed sediments.

Simple Crystalline Rocks from India and Australia.-Judd gives us an account of several simple crystalline rocks from India and Australia. One is a corundum rock composed principally of corundum grains with rutile, picotite, diaspore and fuchsite as accessory constiThe corundum is in part pale colored and in part strongly pleochroic. The grains of the latter extinguish together producing with the former a micro-poicilitic structure. One of the specimens examined came from South Rewah and the other from the Mysore State.

tuents.

Journ. Geol., Vol. IV, p. 160.

Ann. Report State Geol. of New Jersey for 1895. Trenton, New Jersey, 1896, p. 21-61.

Associated with the corundum in the Mysore State is a fibrolite rock.
A tourmaline rock from the Kolar gold field in the same State and
from North Arcot and Salem in Madras, consists of twisted and bent
tourmaline fibres in a matrix of smaller fibres of the same substance.
In the neighborhood of Bingera, New South Wales, two rocks are
found as dykes cutting serpentine. One consists almost exclusively of
green garnets and the other of picotite. The former contains also gold
and chrysocolla.

The Weathering of Diabase.-Mr. Merrill' describes the changes
that have been effected in a granular diabase at Medford, Mass., during
its disintegration into soil. Bulk analysis of the fresh and the weath-
ered rock yielded the following results:

SiO, Al,O, Fe,O, FeO CaO MgO MnO KO Na,O P2O, Ign Total Fresh 47.28 20.22 3.66 8.89 7.09 3.17 .77 2.16 3.94 .68 2.73-100.59 Weathered 44.44 23.19 12.70 6.03 2.82 .52 1.75 3.93 .70 3.73 99.81

The disintegration of the rock is accompanied by a leaching out of its
most soluble constituents. Assuming that the alumnia has remained
unchanged in quantity in the course of the disintegration, the percent-
age of each constituent lost in this process is shown to be as follows:

SiO, AO, Fe,O, FeO CaO MgO MnO K2O Na2O P2O, Ign
18.03 .00 18.10 25.89 21.70 41.57 29.15 12.83 11.39 .00

The paper is full of valuable suggestions that cannot be even referred
to in these notes.

Petrographical Notes.--Transitions from massive anorthosites into augen gneisses and into thinly foliated gneisses and transitions from olivine gabbro into hornblende schists are briefly described by Kemp in a preliminary article on the dynamic metamorphism of anorthosites and related rocks in the Adirondacks.

Pirsson' suggests the use of the word anhedron to express the meaning usually expressed in the phrase 'hypidiomorphic form.' An anhedron is a body with the physical constitution and properties of a crystal but without the crystallographic form. The term may be conveniently applied to the crystalline grains in rock masses.

7 Bull. Geol. Soc. Amer., Vol. 7, p. 349.

Bull. Geol. Soc. Amer., Vol. 7, p. 488. 9 Ib., Vol. 7, p. 492.

GEOLOGY AND PALEONTOLOGY.

The Limestones of the Jenny Jump Mountains, New Jersey. Accompanying the report on the Archean Geology of New Jersey, by Mr. J. E. Wolff is a paper by Mr. L. G. Westgate on the Geology of Jenny Jump Mountain, chiefly interesting on account of the conclusions reached by the author concerning the crystalline limestones of that region.

The area under consideration embraces the northern half of Jenny Jump mountain in Warren county, New Jersey. This mountains lies along the northwestern border of the highland area, and is a sort of outlier or peninsula reaching into the later Paleozoic rocks. The main ridge of the mountain consists of gneisses; the limestone occurs at its extreme northeastern end, with outcrops along the southeast border of the mountain.

The author discusses in detail the position, lithology and relations to the crystalline limestones in other parts of New Jersey, and reviews the views of previous writers as to the age of the Sussex county limestone, which has generally been considered the type and representative of other localities. Mr. Westgate's views are given in the following

summary:

"The crystalline limestones of Warren county are believed to be distinct from and older than the blue magnesian limestone of Cambrian age, which occurs along the northwestern side of the New Jersey Highlands. They are believed to be distinct, for the following reasons."

"1. They differ lithologically from the blue limestone in being thoroughly crystalline, and in containing large amounts of accessory metamorphic minerals."

"2. They are intimately associated with and apparently interbedded with the older gneisses; and gneisses occur also interbedded in the limestone."

"3. They show no intimate association in areal distribution with the blue limestone, nor any tendency to grade into it."

"4. The metamorphic changes to which the white limestones have been subjected are general in their nature, and are not due to the action of the eruptives by which they are cut; so that no sufficient agent is at hand to account for the supposed change from blue into white limestone."

"The white limestones are believed to be older than the blue Cambrian limestone, because (1) they occur in intimate association with the gneisses which are of admitted pre-Cambrian age, and because (2) they have been subjected to general metamorphic forces resulting in great changes, of which the neighboring blue limestone shows no traces."

"That the other crystalline limestones of New Jersey are of the same age as those of Warren county, has not been proved. The theory has generally been that they are. If they are, and if the position taken in the present paper is valid, then the crystalline limestones of Sussex county, and of other places in New Jersey, would also be, as they have generally been supposed to be, of pre-Cambrian or Archean age." (Ann. Rept., New Jersey State Geologist for 1895. Trenton, 1896.)

Unios from the Trias.-Four new Triassic Unios are described by Mr. C. T. Simpson. The collection of which they form a part was obtained from the Dockum beds, a formation underlying the Staked Plains of Texas. Taken as a whole, these Unios closely resemble in form, and are apparently nearly related to those of the Jurassic beds of North America, while 3 of the species bring to mind most strongly the species which now inhabit Europe and western Asia, and a small group belonging to the Mississippi area. The variety of characters displayed by these Triassic Unios go to show that the genus must have been well established at the time the Dockum beds were laid down, thus tending to overthrow Neumayer's theory that the Unionidae were derived from the genus Trigonia, which probably does not date back to a period earlier than that of the shells under consideration. ceeds. U. S. Natl. Mus., Vol. XVIII, 1895.)

(Pro

The Cadurcotherium.-M. Boule calls attention to the recent discovery of the lower jaw of a Cadurcotherium (Gerv.) at Barlière (Haut-Loire). The specimen denotes an animal of the size of a small rhinoceros. It was found in oligocene arkoses associated with a fine mandible of Elotherium magnum, and fragments of Aceratherium, and the remains of turtles. Until now Cadurcotherium has been represented by isolated teeth and fragments of mandibles. The new find is important, showing the animal to be unique among its contemporaries. It presents certain resemblances to South American types-noticably Astrapotherium of the Patagonian Eocene, but is, according to Osborn really related to the rhinocerontic genus Metamynodon.

Notes on the Fossil Mammalia of Europe, V-The Phylogeny of Anoplotherium.-The early attempts at the construction of a phylogeny of the even-toed ungulates, included the genus Anoplo