no. 1821. REVISION OF POTOMAC PLANTS— BERRY. 301 



THE GENUS WIDDRINGTONITES. 



The genus Widdringtonites was established by Endlicher in 1847 * 

 with Tliuites gramineus Sternberg 2 from the Tertiary of Perutz, 

 Bohemia as the type. This he named Widdringtonites ungeri, includ- 

 ing in its synon3^my Juniperites baccifcra linger, Thuia graminea 

 Brongniart, and Muscites stolzii Sternberg. Three additional species 

 were listed, one from the Cretaceous, one from the Wealden, and one 

 from the Lias. His characterization of the genus was as follows: 

 "Folia spiraliter inserta, pleraque squamaeformia adpressa. Stro- 

 bilus globosus, valvatus." 



There are perhaps a score of species ranging in age from the Tri- 

 assic to the Miocene referred to this genus at the present time. It 

 has been commonly used for foliar specimens which resembled the 

 living forms, but which lacked the certainty furnished by associated 

 cones. These are known, however, in a large number of species, 

 many of which, especially those of Tertiary age, being now referred to 

 the still existing genus Widdringtonia. 



Although fruiting specimens of Widdringtonites ramosus are 

 unknown, its immediate successor Widdringtonites reicJiii (Ettings- 

 hausen) Heer of the Raritan and Magothy formations has, in the 

 European material, furnished abundant four-valved cones which 

 induce Velenovsky and Krasser to advocate its reference to Wid- 

 dringtonia. Widdringtonites subtilis Heer, which is common in the 

 later Cretaceous of the Atlantic Coastal Plain, has also furnished 

 somewhat poorly preserved cones of this generic type in material col- 

 lected by the writer in South Carolina and well preserved attached 

 cones in material from the Tuscaloosa formation in Alabama. 



There can be but little doubt of the actual genetic relationship 

 between a number of these Mesozoic conifers and the existing species 

 of Callitris, Widdringtonia, and Frenela, which Eichler lumps into the 

 single genus Callitris Vent. At the present time they constitute a 

 restricted group confined to the Australian region on the one hand 

 (Frenela) and to northern Africa (Eucallitris) and southern Africa 

 and Madagascar ( Widdringtonia) on the other. In former geo- 

 logical periods they were much more abundant. Frenelopsis is 

 recorded in America from Greenland to Texas and Widdringtonites 

 from Greenland to South Carolina. Abroad both types occur abun- 

 dantly in central and western Europe. Like so many other types of 

 plants which were widespread in Mesozoic times they became during 

 the Tertiary more and more restricted in their range until today they 

 are not found at all in the Western Hemisphere. 



i Endlicher, Synop. Conif.. 1847, p. 271. 



' Sternberg, Flora Vorwelt, Tentamen, 1825, p. 38, ph 35, fig. 4. 



