88 Reviews— The Tremadocian of Sweden. 
that the Arenig rocks of Arenig include representatives of all the 
major divisions of the Arenig Series as known elsewhere cannot be 
regarded as other than a welcome simplification of our nomenclature. 
Part III deals with the discovery and detailed description of the 
Fagelsing section, which now, buried beneath a scree of most 
unnecessary rubbish, has yielded much valuable, paleontological 
material and intrinsic evidence in favour of the succession already 
discussed im part II. 
Part IV describes the geographical distribution of localities at which 
the various members of the tabulated succession have been observed. 
Part V is the newest and probably the most valuable portion of the 
whole work; it is a paleontological appendix or monograph of all 
genera and species which are known to occur within the Ceratopyge 
rego (excluding the Tetragraptus phyllograptoides zone) of Scandinavia. 
The forms discussed are referred to 97 species belonging to 52 genera, 
and of these.3 genera and 33 species, besides 3 varieties, are described 
asnew. All Swedish forms (and only some 9 of the Norwegian 
species have not been recognized in Sweden) are represented by one or 
more beautifully executed figures, some of which are only reproductions 
of original type figures, but these are in most cases accompanied by 
one or more carefully drawn new figures of the best obtainable specimen 
of the species. To each species also is appended a full account of its 
older figures and synonymy and a list of the more important localities 
at which it has been recognized. A tabulation and analysis of the 
occurrence of the individual species among the proposed subdivisions 
gives the following result :— 
(d) Apatocephalus zone... ae seh <3. 62 species. 
(ce) Shumnardia zone a x age me 29 species. 
(6) Bryograptus zone a ai Sun sis 16 species. 
(a) Dictyograptus zone... Ro 13 species. 
Of these only two species are common to (a) and (6), 4 to (6) and (¢), 
16 to (¢) and (d), and only the single species Obolus (Bréggeria) 
Saltert is known to range through all divisions. In the final zoological 
analysis attention is drawn to. the preponderance of the trilobites 
(45 species) over Brachiopods (22) and Graptolites (8), but had 
the etragraptus phyllograptoides beds and their equivalent been 
included in the estimate, the result might have been very different, 
and from my own visit to the Ceratopyge regio last Summer I have 
certainly rather retained the impression that that regio is a regio of 
graptolites which includes certain trilobitic and brachiopod - bearing 
bands. 
In conclusion, on behalf of all British students of the Cambro- 
Ordovician rocks, I will venture to offer my thanks and congratulations 
to Professor Moberg and Dr. Segerberg on the completion of this 
useful and monumental monograph of the paleontological aspect of 
the Scandinavian Tremadocian, and will remark that while its 
publication does not actually bring about the elucidation of our 
British Tremadoc rocks it does at least suggest the mode of attack, 
and in the meantime places in our hands a means of identification of 
certain of our material such as we might have prayed for. The 
volume is beautifully printed, and the collotype reproductions of the 
