Reviews and Notices of Books. 337 



a combination of external characters, its place in the cretaceous 

 series would seem to be either with the upper or lower green- 

 sand groups ; the fossil contents of the beds, however, are both 

 abundant and well preserved, and their relation to the series next 

 beneath is unequivocal. Mr Roemer gives a list of upwards of 

 twenty determined species ; with respect to these, we may exclude, 

 as also in all subsequent lists, such forms as seem as yet to be 

 peculiar to the German chalk strata ; and taking those only with 

 which we are acquainted in this country, we find 



Exogyra laciniata, 1. ch.. w. ch., Inoceramus Cripsii (rd. ch.) 

 Hunstanton, Cucullaea glabra, (Bldwn), Pholadomya caudata, 

 Belemnitella quadrata (w. ch.), Nautilus elegans (1. ch), Tere- 

 bratula alata and plicatilis ; against which are placed indications of 

 their several positions in the English series. 



Mr Roemer considers that this subdivision represents the loose 

 sands, with calcareous bands rich in fossils of the wood of Aix 

 and of the Luisberg, and that it is the equivalent of the upper- 

 most white chalk. 



In the lower strata of the hill of Cappenberg are Bourgueti- 

 crinus ellipticus (u. ch.) ; Marsupites ornatus (u. ch.) ; Belemni- 

 tella quadrata, which further support this view. 



Next beneath this arenaceous group is 



A. 2, A Calcareous Clay series of great thickness, and which, 

 though mainly composed of marly beds, yet presents a mineral 

 change in a given direction ; thus, the soft crumbling marls of 

 the east of the basin, as about Beckum, are the equivalents of the 

 compact calcareous beds resembling chalk, which occur at the 

 same level on the west, at about Virden. Like changes occur in 

 lower parts of this cretaceous series ; and in the Aix-la-Chapelle 

 district still greater changes take place within still narrower 

 limits. 



The strata of the hill of Baumberg, near Minister, have yielded 

 the largest assemblage of fossils, by means of which the hard cal- 

 careous strata near Ahaus, the chalk marls north of Coesfeld, and 

 the clay-marls of the hills about and west of Beckum are con- 

 nected with the same subdivision. 



Manon megastoma (1. ch.) ; Siphonia cervicornis fu. ch.) ; Ccelop- 

 tychium agaricoides (u. ch.) ; Parasmilia centralis (u. ch.) ; Bour- 

 gueticrinus ellipticus (u. ch.); Diademaornatum, Ananchytcs ovata 

 (u. ch.) ; Micraster cor. anguinum (u. ch.) ; Chama striata Ignaber- 

 gensis (u. ch.); Terebratula splicata (u. ch.) ; Ostrea vesicularis, (u. 

 ch.) ; Pecten costatus ; Spondylus spinosus (u. ch.) ; Inoceramus 

 Cripsii (1. ch.) ; T. Lamarckii (u. ch.) ; Belemnitella mucronata, (u. 

 and m. ch.) ; B. quadrata (u. ch.) ; Ammintes Lewesiensis (1. 

 ch.) ; Turrilites polypocus (1. ch.) 



This list might be somewhat extended, by including the species 

 quoted from the numerous localities, described by Mr Boemer, on 



