326 Reviews — Yunnan, Western China. 



The other Crustacea described in this memoir are of less general 

 interest. Triasocaris is established as a new genus, and is included in 

 the Syncarida with an expression of doubt that seems to be quite 

 justified. A preoccupied name, Diaphanosoma, has been chosen for 

 another new genus, based on what the author thinks may be a larval 

 form of one of the Decapods. An Estheria is described which, by 

 a rare exception, shows traces of the body and some of the limbs. 

 Finally, Limulites Bronni is redescribed, and a misprint in Schimper's 

 original account is corrected, thereby reducing to one-tenth the 

 m,easurements which had led subsequent writers to attribute to this 

 species the relatively gigantic total length of 1^ metres. 



W. T. Calman. 



II. — Geology of the Province of Yunnan in Western China. 



DURINGr the years 1907—10 several traverses were made by 

 J. Coggin Brown, M.Sc, between Bhamo and Teng-yiieh in 

 the province of Yunnan, the results of which are described in a 

 series of short papers.^ 



The greater part of the area is occupied by a series of gneisses, 

 mica-schists, and crystalline limestones with some intrusive granites. 

 At one locality there is a small development of quartzites and 

 phyllites probably belonging to the Kao-liang Series of Upper Burma. 

 Farther to the east rocks of Ordovician and Silurian age occur. 

 The fossils from these beds have been identified provisionally by 

 F. R. Cowper Reed, M.A. 



In the neighbourhood of Teng-yiieh there are four groups of extinct 

 volcanoes. The rocks extruded from these volcanoes are described 

 by R. C. Burton, B.Sc. Thej- belong to three periods: (1) older 

 bedded pyroxene-andesites ; (2) massive augite-andesites, some of 

 which are olivine-bearing and grade into olivine-basalts ; with these 

 are associated some augite - enstatite - andesites and hornblende- 

 andesites containing nepheline ; (3) olivine-basalts. The last stages of 

 vulcanicity are represented by groups of hot springs. The volcanic 

 rocks are probably of late Tertiary age. 



Mr. Burton notes that these volcanoes lie on the line joining 

 Barren Island, Narcondam, and Mount Popa (Burma) with Loi-han- 

 hun in the E^orthern Shan States. This line is itself a continuation 

 of the Sunda volcanic chain running through Java and Sumatra. The 

 rocks extruded by volcanoes along this line are petrographically 

 similar, consisting of augite-andesites, some hornblende-andesites, and 

 olivine-basalts. The presence of nepheline in some of the rocks of 

 Yunnan is interesting, but it appears to be a rare constituent, and its 

 presence in such quantities cannot, as Mr. Burton thinks, be regarded 

 as placing these rocks in the alkali series, nor need it indicate the 

 proximity of an " Atlantic province ". It is interesting to note that 

 in Yiinnan, as at so many other centres of vulcanicity, the last lavas 

 to be extruded are olivine-basalts. 



In some parts of the area, notably in the plains of Kan-ngai and 

 Nan-tien, there are extensive lacustrine deposits ; these are partly of 

 late Tertiary age, but in places deposition is still going on. 

 ^ Eecords of the Geological Survey of India, vol. xliii, 1913, pp. 173, 206, 327. 



