164 Scientific Intelligence. 



of quiescence, but that the change was a gradual one. He says: 

 "Some of the 'felstones' are augite-andesites and labradorite-an- 

 desites, but little more acidic in character than the olivine-basalts 

 of the great plateaus; and there are abundant examples of lavas 

 of more or less acidic type having been erupted from the central 

 vents from time to time, while the basalts were being ejected. 

 But as I have formerly shown, while the extremely liquid basalts 

 flowed to distances of 40 or 50 miles from their point of origin, 

 the less fluid acidic lavas seldom flowed to distances of more than 

 ten miles and are consequently found confined to the flanks of the 

 volcanoes from which they issued." 



The paper treats at length of the question whether the great 

 centers of eruptions were volcanic centers with subordinate fis- 

 sures of eruption, or merely regions of grouped dikes, and sus- 

 tains, as before, the former of these conclusions. He refers to the 

 eruptions of Hawaii as favoring the view that very small angles 

 of flow are the ordinary method with basaltic lava-streams. These 

 angles over Mt. Loa and Kilauea vary, in general, from seven de- 

 grees to one, and on Oahu and Kauai, in the deep-cut gorges, 

 usually from five degrees to one, and less than one. 



2. On the Genus Tubicaulis of Cotta /by Dr. G. Stenzel, 

 Prof. Realgymnasium at Breslau. 50 pp. 4to, with 7 plates, 

 Mitth. Museum, Dresden, 8th Heft. Cassel, 1889, (Theodor Fis- 

 cher). — This memoir is a full discussion of the fossil tree-ferns of 

 the Tubicaulis type, both historical and descriptive, and a defining 

 of species and genera pertaining to it. The Tubicaulis Solenites 

 of Cotta, a Permian species, is illustrated by transverse sections 

 on plates 1 and 2, and species of other genera on the following 

 plates. The genera differ in the characters of the internal leaf- 

 stems with their leaf-bundles. The genus Asterochlaena of Corda 

 includes the Devonian species Asteropteris Novaboracensis of 

 Dawson. Other genera described are Zygopteris and Anachorop- 

 teris of Corda. The earliest species are two of Asterochlsena in 

 the Devonian ; the larger number occur in the Permian. 



3. Fcmne clu Calcaire cVE/>*bray (Loi?-e Inferieure) , par 

 Charles Barrois. 348 pp. 4to, with 17 plates. Mem. de la 

 Soc. Geol. du Norcl, Tome iii, April, 1889. — M. Barrois, after a 

 stratigraphical account of the region, gives detailed descriptions 

 of 200 species of fossils, with a critical discussion of many ques- 

 tions that come up in connection with them. The faunas of other 

 Devonian regions of Europe are also brought into comparison, so 

 that the work has geologically a continental importance. The 

 relations to the Amei'ican Devonian, with which he is familiar, are 

 also considered. The figures on the seventeen plates are excellent. 



4. Notes on Epidote and Hanksite ; by Dr. C. Bodewig. 

 (Communicated). — Epidote. The epidote which I bought last 

 summer at Manitou Springs at the foot of Pike's Peak offered at 

 first sight nothing worth publishing. A closer investigation 

 showed that we have here the interesting case of a normally devel- 

 oped epidote.* While the epidote of other localities is developed 



* Artini has recently described similar crystals from Elba. — Eds. 



