174 Reviews — E. G. Skeat and V. Madsen — Fossils in Boulders. 



from Professor Zittel at Munich ; and facilities were afforded for 

 comparing the various species with tjpe-specimens in several 

 museums throughout England, France, and Switzerland. 



In additon to the introduction the work consists of two parts : 

 (1) a description of the boulders themselves and the conclusions 

 arrived at as to their age and origin ; (2) a palasontological part, 

 consisting of notes and descriptions of the principal species contained 

 in the boulders. Throughout the work great care has been taken to 

 exhibit the ranges both in time and space of the several species, 

 mostly lamellibranchs, on which the identification of the age of the 

 boulders is based. 



The oldest Mesozoic rock of which evidence exists is represented 

 by boulders of varying materials, in which the shells are both 

 fresh and brackish water forms, unfortunately but ill preserved. 

 These are regarded as having been derived from Eh£elic-Lias beds, 

 which are not yet known. All three stages of the Lias are 

 represented, one boulder from the Jamesoni-zone being quite a 

 little museum in itself. These Lias boulders are found principally 

 on the islands and on the east side of Jutland. They are regarded 

 as having been derived from the eastward ; and the same direction 

 is also claimed for the one Callovian boulder which contains a 

 recognizable Macrocephalites. The authors do not fail to enlarge 

 upon the wide extent of this well-known Jurassic horizon. 



By far the most numerous collection of fossiliferous boulders 

 occurs in the extreme north-west of Jutland, where a Kimeridge- 

 Portland fauna of the Swindon and Hartwell type is well 

 represented. It is considered that these have been derived from 

 beds now concealed in the Skagerrack. The matrix is mostly 

 a calcareous sandstone, more or less ferruginous ; and we can 

 easily believe that anything like typical Kimeridge Clay would hardly 

 survive in a boulder deposit. The Upper Jurassic, as we know, 

 is found in strips along the east coast of Sutherland and Cromarty, 

 almost opposite Jiitland on the other side of the North Sea, where 

 the general assemblage of fossils is said to give evidence of littoral 

 conditions. " Fragments of the grits and limestones of the Upper 

 Oolite, containing their characteristic fossils, are by no means 

 rare in the Boulder-clay of Elginshire, and have also been detected 

 in Aberdeenshire and Caithness" (Judd, in Q.J.G.S., vol. xxix, 

 p. 184). Thus, on both sides of the North Sea there are evidences 

 of a considerable development of beds of Upper Oolite age ; 

 although, if the fossils from the Scotch beds have been correctly 

 determined, they would indicate a somewhat lower Kimeridgian 

 horizon than is shown in the boulders of north-west Jutland. 



" Speaking generally, it may be said that the forms contained 

 in the boulders are such as belong to the middle-European Jurassic 

 province of Neumayr; and in the map accompanying his paper 

 this Scaggerrack region is included in the north temperate zone 

 of Jurassic times, as distinct from the boreal. The beds were 

 laid down under rather similar but more uniform conditions than 

 those of Boulogne, and indicate possibly an eastward continuation 



