178 Reviews — Mining in the Dutch East Indies. 



Silurian type of glabella is found in Malladaia by tbe partial loss or 

 reduction of tbe third pair of lateral lobes. ^ ' Ci-yphina ^ differs 

 mainly from ^Asteropyge in tbe number and sbape of tbe marginal 

 pygidial spines, and ^Proholium ^ is characterised chiefly by tbe 

 possession of a long frontal rostrum on the bead-shield, rudiments 

 of which are found in Silurian species. 



{To be continued.) 



I^ IB "V" I lEJ 'V^ S. 



Jaarboek van het Mijnwezen in Nederlandsch Oost- Indie. 

 Drie en dertigste Jaargang, 1904. Wetenschappelijk Gedeelte : 

 Geologie eines Teiles von West Borneo, nebst einer kritiscben 

 Uebersicht des dortigen Erzvorkonimens, zusammengestellt von 

 N. Wing Easton, Oberbergingenieur. Zu diesem Werke 

 gehoeren : Ein Atlas und eine Mappe mit Microphotographien. 

 Batavia, Landsdrukkerij. 



Yearbook of Mining in the Dutch East Indies. 33rd year, 

 1904. Scientific Part : Geology of a Part of West Borneo, with 

 a critical review of its Ore Deposits, composed by N. Wing Easton, 

 Chief Mining Engineer. To this work belong an Atlas and a Map 

 with Micropbotographs. Eoyal 8vo : pp. xv, 542, with folio 

 Atlas of 11 coloured geological plates, 1 plate of sections, and 

 1 of fossils ; also 120 micropbotographs of Borneo rocks, on 

 21 plates, with explanatory text. Batavia : State Printing Office. 



A BOUT two years since * we called the attention of our readers 

 xJL to tbe elaborate work of Dr. Molengraaff describing his 

 geological explorations in Centi'al Borneo ; we have now before 

 us another volume, somewhat more restricted in character, giving 

 an account of the geology of a part of tbe Residency of West Borneo, 

 which includes the Kapuas district and the territory to the north 

 of it. Mr. Wing Easton, the author of tbe work, has been about 

 fourteen years engaged, on the part of the Dutch Colonial Govern- 

 ment, in mining and geological exploration in this extensive region, 

 and, judging from his descriptions, its topographical and geological 

 features are generally very similar to those of Central Borneo. The 

 country is by no means an ideal one for geological investigation, for 

 there are hardly any well-defined highways, land communication 

 is carried on along narrow footpaths or tracks, often through dense 

 forests, and rock exposures are, as a rule, only met with on the 

 banks of streams. Moreover, the apparently entire absence of fossils 

 in tbe older sedimentary rocks of Borneo, and their extreme rarity 

 and limited distribution in higher strata, form a serious hindrance 

 to tbe determination of the real stratigraphical sequence, and, failing 



' Oehlert: Bull. Soc. Geol. France, ser. in, vol. xxiv (1896), p. 843, woodcut 

 fig. 12. 



* Id. : op. cit., ser. ni, vol. xvii (1889), p. 758. 



' Ibid., p. 763, pi. xviii, fig. 6. 



« Geol. Mag., Dec. lY, Vol. X (1903), p. 167. 



