FOREIGN WORK AMONGST THE OLDER ROCKS. 15 



Tennessee, Virginia, Maryland, Pennsylvania, New Jersey, 

 New York and Vermont were all deposited in Lower 

 Cambrian times, and contain the Olenellus fauna. The 

 overlying limestones have the Olenellus fauna in their 

 lower portions in Vermont, Eastern New York, New 

 Jersey and Pennsylvania. It is interesting to find that these 

 limestones contain faunas of ages up to and including the 

 Trenton. It is not clear at present where the line between 

 Cambrian and Ordovician should be drawn in these lime- 

 stones. The existence of many faunas in this accumulation 

 of clear water limestones is of particular interest to British 

 geologists when it is remembered that the Durness Lime- 

 stone of the North-west Highlands of Scotland is generally 

 looked upon as if belonging to the American type. Atten- 

 tion may be drawn to the adoption of the term Ordovician 

 by Walcott, one of the principal American authorities on 

 the Lower Palaeozoic rocks. Its universal use seems to be 

 but a question of time. 



A paper by Andersson (12) is of interest as bearing, on 

 the classification of the Lower Palaeozoic beds of Scan- 

 dinavia. He describes the fossils found in loose blocks on 

 the south-east of the island of Oland, and places the beds 

 which have yielded the blocks in the folio wins: ascendino- 

 order : Macruruskalk, grey Trinucleus Shales, red Trinu- 

 clens Shales and Limestones, and Limestones with Leptcena 

 Schmidti, Tornq, including all in the Lower Silurian 

 (Ordovician). The position of the Leptczua limestone has 

 been disputed, but the accumulation of evidence all points 

 to the correctness of Andersson's grouping. 



A large number of papers bearing on the Lower 

 Palaeozoic rocks are purely palaeontological, many of them 

 referring to the trilobites (13), and it will be noted that 

 additional information concerning the appendages of these 

 creatures is forthcoming. Simultaneously, our knowledge 

 of the minute structure of the graptolites is increasing ; 

 Wiman (14) describes the nature of certain Diplograpticls 

 from a fragment of the " Ostseekalk " of Bornholm, dis- 

 cussing the relations of the sicula, virgula, and hydrothecae 

 to one another, whilst all geologists will welcome Jaroslav 



