Johnson and Gii.moke — Libocedrus audits Conein the Irish Tertiary. 69 



forms. Tlie seeds of Libocedrus, Thuya, and Biota are, however, easily distinguish- 

 able, being one-sidedlj', two-sidedly, or not at all winged, respectively. 



The earliest ]-ecorded Zihocedrus, L. crdacca, Heer (4), is from the Upper 

 Cretaceous beds of Atane iu Greenland. Its lateral leaves are basally united for 

 some distance. All the leaves are completely adpressed, giving the twigs, which 

 are opposite and 2 mm. wide, parallel sides. Though Heer lays stress on the 

 oppositeness of the lateral branches, the twig he figures (op. cit., Tf. xliii, fig. Id) 

 shows alternate branches only. Very similar to /. cretacea and more highly 

 suggestive of L. da'urrcns of California is Z. Sabiniana,'iieev, from the Spitzbergen 

 Miocene (5). The foliage and opposite branches (most Cupressincac have alternate 

 branches) suggest Libocedrus. This view is practically confirmed by the occur- 

 rence in the same beds of seeds wliich liave the characteristic oblique almost 

 one-sided wing of the IJboeedrus seed, well shown in Heer's illustrations. In his 

 elaborate investigation of fossil woods from Greenland, ]'>eust (2) finds, by com- 

 parison of the fossi] and recent woods, tiiat Libocedrus was a common tree in the 

 Lower Miocene of Greenland, llis identification of the Greenland fossil as 

 Libocedrns is not accepted by Schenk (18), The detailed illustrated account of 

 L. Sabiniana occurs in tlie second volume of Heer's Flora fossilis Arctica (5), but 

 appears to have been overlooked by Seward (15), as his rejection of Heer's identi- 

 fication of the fossil as Libocedrus is based on a short note in the seventh volume (6), 

 almost confined to a statement by Heer that the fossil from the Atane Tertiary 

 beds in Greenland agrees with that (the type) from Spitzbergen. He adds tliat a 

 cone-scale from Hare Island probably belongs to L. Sabiniana. L. gracilis, Hr. (7), 

 which is also recorded from the Miocene of Spitzbei gen, is more like L. j^luniosa 

 (L. Doniana) of New Zealand in habit, and L. Chilensis of South America in its 

 associated cone-scales. 



The most widely distributed fossil assigned to Libocedrus is L. salicornioides 

 Unger (17). It occurs in numerous localities in the Tertiary beds of Europe, 

 from the Eocene to the Upper Miocene. Opinions have differed considerably as 

 to its interpretation. Thus Saporta (l:-!) finds his material from Armissan in all 

 points identical with the type Thuytes salicornioides Unger from (Croatia, but 

 adds it is not at all certain that it is a Libocedrus. More perfectly preserved 

 fertile specimens may, he thinks, show it is Viscum, for which he supplies a then 

 appropriate diagnosis. The occurrence of L. salicornioides in the Interbasaltic 

 beds of North-East Ireland is not surprising, as the species is known from the 

 amber beds of the llaltic and from (Jeutral Europe. Gardner (.3) reported the 

 genus doubtfully as Libocedrus adpressa sp. n. from the Woolwich beds at Bromley 

 in Kent. The evidence has since been rejected as insufficient (op. cit., p. ?>08). 

 It is of interest to add that Ludwig (12) records Libocedrus salicornioides from 

 below the columnar basalt of Holzhausen. This material, like ours from Washing 

 Bay, was found in the form of single joints. 



