. Fossil plants : for students of botany and geology . Paleobotany. XLV] DAMMAKITES 249 Dammarites borealis (Heer). Though it -is clearly impossible to define with any precision the limits of species based on detached scales varying considerably in size and shape, several types have been recorded, particularly from different localities on the Atlantic Coastal plain of North America^. The larger forms may con- veniently be included in Dammarites borealis Heer and smaller forms are illustrated by Protodammara speciosa Holl. and Jeff.^ It is probable that these two types are generically identical
. Fossil plants : for students of botany and geology . Paleobotany. XLV] DAMMAKITES 249 Dammarites borealis (Heer). Though it -is clearly impossible to define with any precision the limits of species based on detached scales varying considerably in size and shape, several types have been recorded, particularly from different localities on the Atlantic Coastal plain of North America^. The larger forms may con- veniently be included in Dammarites borealis Heer and smaller forms are illustrated by Protodammara speciosa Holl. and Jeff.^ It is probable that these two types are generically identical, but the name Protodammara implies the presence of certain structural features while Heer's species is founded on casts or impressions. A specimen of the latter species from Greenland is shown in fig. 733, the scale is 22 mm. broad and is characterised by several parallel lines, either vascular bundles or resin-canals, and the white patches represent some exuded , . , „,i ^ , ^ Fio. 733. Dammarites bo- resmous material. Other Greenland ex- ^^^^.^ Cone-scale from amples are more elongated basally and are igdlokungnak, West identical in shape with the smaller scales Greenland. (Stockholm from Staten Island seen in fig. 758, E, F, page 323. Fossils of similar form were described by Heer from the same locality as Eucalyptus Geinitzii^. Krasser* and some other writers have retained the generic name Eucalyptus on the ground of association with Eucalyptus-like leaves. Hollick speaks of scales like D. borealis as 'among the most abundant and charac- teristic remains found in the Cretaceous deposits of America and Europe^': he adds that the name Dammarites is chosen for the sake of convenience rather than from a conviction that it represents their true generic relationship. Newberry in describing this type from the Amboy clays states that some of the scales have grooves, corresponding to the dark lines in fig. 733, filled with amber«, and anatomical evidence derived from Protodammar
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