DO DESCRIPTIVE CATALOGUE 



certainly subject to well-marked seasons (see p. xxii). Unfor- 

 tunately, there appears to be no evidence from vertebrate or 

 invertebrate palaeontology regarding the land-conditions of the 

 time. 



If Gothan's data are correct, they indicate, as he points out, 

 that the origin of the Abietinean stock may be circum-polar ; 

 but the great obstacle to drawing any of the tempting deduc- 

 tijons regarding the earlier distribution of these families is, 

 that the work of Gothan on the polar " Jurassic " woods must 

 be taken with considerable caution when applied to points of 

 stratigraphical importance, for, as Burckhardt (1911) has demon- 

 strated, their age is by no means beyond question. Indeed, it 

 appears to be very unlikely that they are really Jurassic. From 

 data provided in Nathorst's own work (1 ( J10), Burckhardt con- 

 cludes that "die pflanzeniiihrenden Schichten (' Viixtforandc 

 Lager ') ebenso wie der Basalt mitsamt den von Gothan beschrie- 

 benen foissilen Holzern jiinger sein miissen als das Keocoin 

 mit Atfcc.Ua Keyterlingi da sie dieses transgressiv iiberdeeken." 

 ..." Die von Gothan untersuchten fossilen Hol/er des Kb'nig- 

 Karl-Landes haben also gar keine Bedeutung fiir die Frugo 

 jurassichcr Klimazonen, da sie nicht jurassisch sind ..." 



These plants, or part of them ;it least, were described by 

 Hecr as Cretaceous (probably equivalent to the Gault), and if 

 that be their age they represent a flora more directly com- 

 parable with that of the Lower Greensand than one in an 

 ancestral position toward it. 



Regarding England, where the stratigraphical position of the 

 fossils is securely known, the strongly marked growth-rings 

 found in so many of them, coupled with the remarkable and 

 total absence of the Araucarinea?, is highly suggestive of a 

 relatively cool temperate climate for the district in Apt inn 

 times, though one must not forget that several species of Bennet- 

 tites still lingered on (see p. 23, et seq.). 



Family TAXODINE^E. 



Eight principal living genera compose this family, from 

 various parts of the world, some with very local and restricted 

 distribution. Several of the living genera are certainly repre- 

 sented among the fossils, and also a large number of rather 



