no.1769. FOSSIL PLANTS OF THE POTOMAC GROUP -BERRY. 635 



linear-lanceolate to elongate-lanceolate. Length unknown, apparently 

 ranging from 10 cm. to 30 cm. Maximum width 1.2 cm. to 5 cm. 

 Texture coriaceous. Midrib rather stout and prominent. Lateral 

 veins tliin hut distinct, especially on the lower surface, more or less 

 closely placed, parallel, curving backward from the midrib and then 

 straight or slightly curved upward to the margin. Angle of divergence 

 wide, 45° to 90°. Veins either simple or forked, the forking usually 

 near the base, both kinds often shown on a single specimen. 



This species is based entirely upon very fragmentary material, 

 which served Fontaine for the differentiation of five species of 

 Angiopteridium and two species of Anomozamites. There is absolutely 

 no ground for the reference of any of the material to the genus 

 Anomozamites and it is all obviously identical. There is some slight 

 variation from specimen to specimen, for example, the midrib is some- 

 what less stout in Angiopteridium nervosum and densinervi as delimited 

 by Fontaine and the angle of divergence is somewhat more acute 

 in the latter, but these are not characters of specific value. If 

 similar recent fronds, such as those of Oleandra, Angiopteris, or 

 Marattia, be examined the size of the midrib, the remoteness or 

 closeness of the lateral veins and their angle of divergence will be 

 found to vary through much wider limits, a single frond often exhibit- 

 ing the extremes in this respect. 



A single specimen from Fredericksburg, figured by Fontaine " and 

 showing apparently the basal portion of three pinnae lying in the 

 same plane and direction and two of them attached to stout bits of 

 rachis, is the only evidence that the fronds were pinnate and not 

 simple. These may represent aerial stalks or they may equally 

 well be interpreted as fragments of a rhizome or a rootstock. 



This species is not common in the Potomac group and is confined 

 to the Patuxent formation. Similar remains are described from 

 both the Knoxville and Horsetown beds of the Pacific coast and 

 similar fragmentary specimens are described by Saporta '' from the 

 Valanginien of Portugal and referred to Schimper's genus Oleandri- 

 dium. In the European Wealden there is Oleandridium beyrichii 

 Schenk c from Germany and England which Seward refers to 

 Tseniopteris, and two other forms of questionable distinctness which 

 the latter author describes from the English beds.'' Oleandra arctica 

 Ileer c from the Kome beds of Greenland may be compared with 

 the Potomac Tamiopterids. Newberry ' identifies this species in the 



aMonogr. U. S. Geol. Surv., No. 15, 1X90, pi. 29, 6g. 9. 



& Saporta, Flora Fobs. Portugal, L894, p. 85, pi. 1">, fig. :'>; pi. Hi, fig. is. 



cSchenk, Palaeontographica, vol. L9, L871, p. 221, pi. i".t, figs. 6, 7. 



dSeward, Wealden Flora, pt. I, L894, pp. 127, L28. 



eHeer, flora Foss. A.rct., vol. :{. pt. 2, L874, \>. 38, pi. L2, figs. •"> 11. 



/Newberry, Amor. Journ. Sci. (ser. 3), vol. II, L891, p. 201, pi. I I. fig. !). 



