Geology. 319 



the fauna being essentially boreal. (2) The Horsetown horizon, 

 beginning with the close of the Knoxville and continuing to the 

 horizon representing the great Chico overlap, the fauna being 

 typically subtropical. (3) The Chico or uppermost member as 

 represented by the Phoenix beds, and by those of Wallala and 

 other points in Lower California. The Chico is divisible into two 

 horizons in the Sacramento Basin, and perhaps elsewhere, the later 

 Chico fauna being characterized by a large development of gas- 

 teropods and lamellibranchs. 



The general order of regional movement, more particularly in 

 the Great Valley, has been downward from the first, but not con- 

 tinuously so. The different members of the Cretaceous series of 

 California find their counterparts all along the American border 

 of the Pacific, and are to be closely correlated with the recog- 

 nized members of the interior basins of both hemispheres, as shown 

 by a parallelism of crustal movement and development much more 

 general than commonly supposed, and by extensive faunal resem- 

 blances, amounting often to close specific affinity or even specific 

 identity. The faunae of the Pacific coast Cretaceous are mostly 

 marine, and of littoral rather than deep-sea origin. g. e. w. 



3. Geology of German Southwest Africa. — At a meeting of 

 the Geological Society of South Africa, held at Johannesburg, 

 July 11th, 1904, Mr. F. W. Vorr presented a paper on the geol- 

 ogy of the region east of Walfish Bay and between the Quisep 

 and Swakob Rivers. 



The country is in large part desert, covered with quicksands 

 and sand dunes. The greater part of the country exhibits the 

 same geological features as the oldest members of the geological 

 formation in South Africa. The base of the district consists of 

 schistose rocks, exhibiting large variety ranging from fine schists 

 to coarsely banded gneisses. These metamorphic rocks are 

 ascribed to the Archean Period. The amphibolite layers in the 

 gneisses are believed to be extrusives of a diabase type. There 

 are also intrusive masses of granite. A few outcrops of sand- 

 stone occur and are classed as Lower Devonian. The appearance 

 of copper ore in this district has been investigated by Mr. Yoit, 

 and it seems probable that extensive deposits of medium grade 

 ore will be found. It is of interest to note that volborthite (which 

 is elsewhere a rare mineral) is of very frequent occurrence in 

 this district. The rocks collected have been studied microscopi- 

 cally by Professor Beck, of Freiburg. 



4. Liassic and Oolitic Floras of England. — Being Part II of 

 the Jurassic Flora represented in the British Museum ; by A. C. 

 Seward. 183 pp., 13 pis. — This number of the British Museum 

 catalogue forms the completion of a treatise on fossil floras of 

 the Trias, Rhsetic, Lias, and Oolite of England. Although the 

 fossils included in Part II are for the greater part fragmentary, 

 the high degree of care bestowed on this as on all the parts gives 

 the descriptions importance in themselves aside from the fact that 

 they belong to a series that is indispensable to every student of 

 fossil plants and plant distribution. 



