SCIENTIFIC INTELLIGENCE.

I. GEOLOGY AND MINERALOGY.

1. The Appendages, Anatomy, and Relationships of Trilobites; by PERCY E. RAYMOND. Mem. Connecticut Acad. Arts and Sci., vol. 7, 169 pages (quarto), 11 pls., 46 text figs., 1920.-The sudden death of Professor C. E. Beecher in 1904 left unfinished his studies of the ventral anatomy of trilobites, and it is fitting that one of his students, Professor Raymond, of Harvard, should take up the work and bring it to a successful conclusion. The splendid memoir which results, dedicated to Beecher and having a portrait of him as its frontispiece, contains many of his drawings and photographs illustrating the ventral anatomy of the trilobites, here reproduced for the first time.

The memoir consists of four parts. In Part I are described in detail the ventral appendages of nine American genera: Neolenus, Isotelus, Ptychoparia, Kootenia, Ceraurus, Calymene, Acidaspis, Cryptolithus, and Triarthrus. Excellent pen and ink restorations are presented of Neolenus, Isotelus, Triarthrus, Ceraurus, and Cryptolithus. With the exception of the antennules in all of the genera, and the caudal cerci known only in Neolenus, all the appendages are biramous. These rami always consist of endopodites and exopodites, and the author sees no other appendages like those described by Walcott in Neolenus and Calymene. The inner appendages (endopodites) functioned as locomotory organs, either for crawling, swimming, or burrowing, the particular method varying with the species. Doctor Raymond considers the exopodites to have functioned primarily as gills, and only secondarily as swimming organs, and suggests that where the pygidium is large, it served as a swimming organ. He agrees with Beecher in the latter's homology of the cephalic appendages with those of the higher Crustacea, the first pair of biramous appendages being homologous with the antennæ, and the other three pairs representing the mandibles and the first and second pairs of maxillæ.

In Part II are considered the internal structures and habits of trilobites. Except for the eyes, data are rather scanty. The intestinal cavity is thought to have been enlarged beneath the glabella and thence to have passed straight backward beneath the middle lobe of the test. Muscles, nervous system, various glands, heart, etc., are discussed to the extent the structures are known. The median ocellus" or "dorsal organ" of the glabella of many trilobites is interpreted as the point of attachment of a ligament supporting the heart. The habits of life are considered with respect to locomotion, food, and feeding, and it is found that in maturity trilobites were adapted to planktonic, nectonic, and benthonic environments, according to species. It is suggested that in the early stages of their racial history the trilobites were carnivorous, but that even before Middle Cam

brian time some had become vegetable feeders and that in the late Cambrian most of them appear to have become omnivorous. A few may have been mud eaters.

Part III discusses the relations of trilobites to the other groups of the Arthropoda, and the conclusion is reached that the trilobites are the most primitive members of the phylum and either directly or indirectly ancestral to all the other orders. The ancestor of the trilobites is thought to have been a "soft bodied, free swimming, flat, blind or nearly blind animal of few segments,' and Naraoia compacta Walcott is suggested as the most primitive of all known trilobites and hence closest to the ancestral stock. A diagram showing the interrelationships, time of origin, and duration of the Arthropoda is given in figure 41 on page 150. Among the striking phylogenetic conclusions are: (1) that the insects probably had their origin in the trilobites, though not directly, but through some tracheate stock which was directly ancestral to the diplopods and chilopods as well; (2) that the diplopods, chilopods, and the higher Crustacea had their origin in the trilobites back of the Cambrian; (3) that the arachnids, eurypterids, and horseshoe crabs arose in the xenopods (a new subclass of Crustacea), and that this stock also developed out of the trilobites in pre-Cambrian times; (4) that the copepods had their origin in the most primitive of trilobites (Hypoparia), independently from the rest of the higher Crustacea; (5) that the Arthropoda "constitute a natural monophyletic group," of which the Trilobita are the ancestral, oldest known stock; and (6) that the appendages of all other arthropod lines "could have been derived from those of trilobites."

Part IV gives descriptions of the appendages of individual specimens of Triarthrus becki Green and Cryptolithus tesselatus Green.

An excellent bibliography and an historical review of the investigations relating to trilobite appendages are other parts of the work. The forty-six text figures serve their purpose well, and there are in addition eleven plates, of which ten show photographs or drawings made by Professor Beecher or under his direction. On Plate 11 is given an excellent restoration of Ceraurus pleurexanthemus, drawn by Doctor Elvira Wood.

W. H. TWENHOFEL.

2. The Geology of Hardin County, and the Adjoining Part of Pope County; by STUART WELLER, with the collaboration of CHARLES BUTTS, L. W. CURRIER, and R. D. SALISBURY. Illinois Geol. Survey, Bull. 41, pp. 416, 11 pls., 30 text figs., 1920.-In this very detailed county report are described the Devonian, Mississippian, and Pennsylvanian formations, which together have a thickness of over 3,500 feet. The book is particularly valuable because of the detailed description of the Mississippian sequence. The region has been bowed up into an immense dome, then broken into a complex series of blocks and intruded by dikes, sills, and

plugs that are rich in the ores of fluorspar, lead, and zinc, the distribution, occurrence, and origin of which are discussed by Currier. The general geography is treated by Salisbury.

The most interesting portions are those dealing with structural geology (Part II), stratigraphic geology (Part III), and paleontology (Part VI), all by Weller and Butts. The Mississippian is divided into a "Lower" series embracing the Kinderhook, Osage, Meramec, and Ste. Genevieve, and an "Upper" for the various members of the Chester, but both are regarded as of one period. The well known differences of opinion between Weller and Ulrich regarding the sequence and correlations of the various Chester members are clearly stated by the former. Only the fossils which are more important stratigraphically are described and figured photographically.

C. S.

Devonian Floras, a study of the Origin of Cormophyta; by E. A. NEWELL ARBER. Pp. 100, 47 figs. and portrait. Cambridge (University Press) 1921.-It would be manifestly unfair to a friend who has gone to criticise a work left as a first draft by the author. It seems to the reviewer, however, that the "critical review" of Devonian floras is so incomplete as to be of little value as a work of reference, and that it would have been kinder to Arber's memory to have left at least this part of the work unpublished.

Arber considers that the Devonian floras represent an earlier, which he calls the Psilophyton flora, and a later, which he calls the Archæopteris flora. Psilophyton itself is regarded as identical with the petrified remains described as Rhynia, and these along with Arthrostigma, Pseudosporochnus, Thursophyton, etc., are considered as Thallophytes which, anatomically, stand half way between existing Thallophyta and vascular plants. These are the Procormophytes and are not reduced Cormophytes or in any way related to the existing Psilotales, but represent part of the ancestral stock of the unrelated phylae Sphenopsida, Pteropsida and Lycopsida, or what I would call the Arthrophyta, Pteridophyta and Lepidophyta. That is to say, the Sphenophyllum-CalamiteEquisetum phylum, the Lepidodendron-Sigillaria-Lycopod phylum, and the Fern phylum along with higher derivatives, are of independent origin from an algal ancestry. Arber contends that the modern Psilotales are also of algal origin but at a much later geological period and independently, as also are the Bryophyta. Most botanists will agree to the algal ancestry of the so-called vascular plants as there is really no alternative. That they are as polyphyletic as Arber thought is extremely doubtful, although this is the position taken by Church in his recent speculation on the subject.

Both Arber and Church are influenced by the tradition of primitive oceans on a cooling globe, which may or may not have been true. In any event it should be remembered that the duration of time since the earth first became suitable as an abode for

terrestrial life probably reached as far back beyond the oldest known land flora of the Devonian as the interval that has since elapsed and there would have been ample time to have developed the anatomical features of Rhynia by reduction, as seems to have been the actual case in the Psilotales. Serious doubts as to the primitiveness of these types arise when the Cordaitalean woods of the Devonian, which are ignored by Arber, are considered. The Archæopteris flora is regarded by Arber as truly pteridophytic and ancestral to that of the Lower Carboniferous.

Morphologists will be interested in the unfinished outline of the evolution of the stele sketched in Chapter 7, the stages of which are set forth as-first, a single protoxylem group formed by the simultaneous modification of a set of procambial elements, which took place independently in the main axis and branches : second, the substitution of continuous for purely initial transformation, resulting in protoxylem and xylem: third, the formation of a secondary cambium and secondary wood.

E. W. B.

4. Le Platine et les Gites platinifères de l'Oural et du Monde; LOUIS DUPARC and MARGUERITE-N. TIKONOWITCH. Quarto. 542 pp., 96 figs., 11 pls. and an atlas with 5 maps and 8 pls. 1920.Professor Dupare with various assistants has been studying the platinum deposits of the Ural Mts. and elsewhere for the past twenty years. The partial results of these researches have been published from time to time in various papers and books. In the present work all this material has been gathered together in an exhaustive monograph.

The study of the geology of the platinum districts shows that the mother-rock of the platinum is primarily dunite and to a much less extent pyroxenite. In the Ural Mts. the platinum-bearing rocks have segregated from the original magma in such a way that the center of the mass is now a dunite which is surrounded by a belt of pyroxenite and the whole enclosed by extensive areas of gabbro. The latter rock is practically free from platinum, however. While the book is chiefly concerned with the deposits of the Ural region a chapter is devoted to platinum. occurrences elsewhere. The book includes also chapters on the mining methods, metallurgy and uses of the metal. W. E. F.

5. Elemente der physikalischen und chemischen Krystallographie; by PAUL GROTH. Pp. 363, 4 pls., 962 figs. in text and 25 stereoscopic charts. Berlin, 1920.-This is a book which treats the various phases of the subject from the standpoint of the chemist. In the chapter on crystals, for instance, the illustrations are all taken from the products of the chemical laboratory. The book is profusely illustrated, for the most part by small but well reproduced figures. The book would have been considered a notable achievement if published under normal conditions and under the present circumstnaces it becomes doubly remarkable.

W. E. F.

6. Crystallography. A Series of Nets for the construction of

Models illustrative of the simple Crystalline Forms; by JAMES B. JORDAN. London, 1921 (Thomas Murby and Co.).-This consists of a series of charts giving in outline form figures from which models of various simple crystals may be produced by folding. Considering the difficulty and expense involved in acquiring wooden crystal models at the present time pasteboard models made in this way might prove very useful.

W. E. F.

7. New Mineral Names; by W. E. FORD (communicated-continued from vol. 49, pp. 452-453, June 1920):

=

Armangite. G. AMINOFF and R. MAUZELIUS. Geol. För. Förh. 42, 301, 1920. Hexagonal-rhombohedral. C= 1.3116. Prismatic habit. H. 4. G. 4.23. Poor cleavage || c (0001). Color black. Streak brown. Optically. Indices very high. Comp.-Mn, (ASO). Found in a coarse crystalline mixture of calcite and barite from Långban, Sweden.

Brannerite. F. L. HESS and R. C. WELLS. Jour. Frankl. Inst., 189, 225, 1920. In rough prismatic crystals. Also granular. Color black with brownish yellow coating due to alteration. Streak, dark greenish brown. Opaque. Conchoidal fracture. H. = 4.5. G. 4.5-5.4. n = 2.30. Radioactive. Comp.-A metatitanate, essentially (UO,TiO,UO2) TiO3. Found in gold placers in Stanley Basin, Idaho. Named after Dr. John C. Branner.

Cesàrolite. H. BUTTGENBACH and C. GILLET, [Ann. Soc. Geol. Belg.], Amer. Min., 5, 211, 1920. In cellular masses. Color steel-gray. H. = 4.5. G. = 5.29. Comp.-A manganate of lead, H.PbMnOs. Occurs with galena at Sidi-Amer-ben-Salem, Tunis. Named after Prof. G. Cesàro.

Dixenite. G. FLINK, Geol. För. Förh., 42, 436, 1920. Hexagonal. As aggregations of thin folia, often radiating and sometimes in globular masses. H. 3-4. Basal cleavage. Color nearly black but red by transmitted light. Luster resinous to metallic. Uniaxial, +. n 1.96. Comp.-MnSiO,.2Mn, (OH) AsO,. Found associated with hematite, dolomite, and serpentine at Långban, Sweden. Named from di two and έevos stranger in allusion to the unusual association of SiO, and As,O.

=

Flagstaffite. F. N. GUILD, Amer. Min., 5, 159, 1920. Orthorhombic. abc 1.2366:1:0.5957. In minute prismatic crystals. Colorless and transparent. n = 1.51. G. = 1.092. Comp.-C12H240g. Melts at 100°C. Very soluble in warm alcohol and recrystallizes on cooling. Found in the cracks of buried tree trunks near Flagstaff, Arizona.

Higginsite. CHARLES PALACHE and E. V. SHANNON. Amer. Min., 5, 155, 1920. Orthorhombic. a b c = : 0.62421 : 0.7940. In small prismatic crystals with pyramid and dome terminations. H. 4.5. G. 4.33. n = 1.745. Ax. pl. || (010). Marked pleochroism, X green, Y yellow-green, Z blue-green. = Comp. An arsenate of copper and calcium, CuCa(OH) AsО1. Fusible at 3, coloring the flame at first pale blue and then blue