THE FLORA OF THE EARLY MESOZOIC. 185 



tatives of the 8. gigantea. Their leases are stiff and 

 sharp-pointed, are thinly set round the branches, and lie 

 forward in the same way : the egg-shaped cones are in 

 some cases similar. 



There are, however, in the early Tertiary six species, 

 which fill up the gap between 8. sempervirens and 8. 

 gigantea. They are the S. Couttsice, 8. affinis, Lesq., 

 8. imbricata, Hr., 8. sibirica, Hr., 8. Heerii, Lesq., and 

 8. biformis, Lesq. Of these, 8. Couttsice, Hr., is the 

 most common and most important species. It has short 

 leaves, lying along the branch, like 8. gigantea, and 

 small, round cones, like 8. Langsdorfii and sempervirens. 

 Bovey Tracey in Devonshire has afforded splendid speci- 

 mens of cones, seeds, and twigs, which have been described 

 in the " Philosophical Transactions. " More lately, Count 

 Saporta has described specimens of cones and twigs from 

 Armissan. Specimens of this species have also been found 

 in the older Tertiary of Greenland, so that it must have 

 had a wide range. It is very like to the American 8. 

 affinis, Lesq. 



In the Tertiary there have been already found fourteen 

 well-marked species, which thus include representatives 

 of the two living types, 8. sempervirens and 8. gigantea. 



We can follow this genus still further back. If we go 

 back to the Cretaceous age, we find ten species, of which 

 five occur in the Urgon of the Lower Cretaceous, two in 

 the Middle, and three in the Upper Cretaceous. Among 

 these, the Lower Cretaceous exhibits the two types of the 

 Sequoia sempervirens and 8. gigantea. To the former 

 the 8. Smithiana answers, and to the latter, the Beichen- 

 bachii, Gein. The 8. Smithiana stands indeed uncom- 

 monly near the 8. Langsdorfii, both in the appearance of 

 the leaves on the twigs and in the shape of the cones. 

 These are, however, smaller, and the leaves do not become 

 narrower toward the base. The 8. pectina, Hr., of the 

 Upper Cretaceous, has its leaves arranged in two rows, and 



