292 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



Description. — Twigs alternate, branching copiously and more or 

 less crowded, with a tendency toward a fastigiate arrangement in 

 numerous specimens. Leaves thick, keeled dorsally, ovate in out- 

 line, often broadly so, acuminate, often slightly recurved, rather 

 crowded and more or less appressed, but larger and much more 

 divergent than those of the genera Arthrotaxopsis or the Lower Cre- 

 taceous species of Widdringtonites. Phyllotaxy spiral. Cones small, 

 globose or oblate spheroidal, scales few in number, short and thick, 

 truncate distally, becoming more or less divergent with age. 



This species is very common at a large number of Lower Cretaceous 

 horizons in both Europe and America, and it has also been recorded 

 from the Cenomanian in Portugal, Saxony, and Austria (Lesina). 

 It is present in the Neocomian of Portugal and Westphalia and 

 doubtfully in beds of this age hi Russia. It is present in the Wealden 

 of England and Germany, the latter being the type area. It is also 

 recorded from the Urgonian of Portugal and is probably present in 

 the Kome beds of Greenland. In tins country it is recorded from 

 the Kootanie of Montana and the Fuson formation of the Black 

 Hills. It is a very abundant form in the Potomac group, and occurs 

 at numerous localities ranging in age from the oldest or Patuxent 

 beds to the youngest or Patapsco beds, a range similar to but some- 

 what less in time than that ascribed to it in Portugal, where Saporta 

 recognizes it from the Neocomian to the Cenomanian. Some of the 

 numerous specimens from the Kome beds of Greenland, winch Heer 

 described first as Widdringtonites gracilis 1 and afterwards as Cyparis- 

 sidium gracile, 2 are probably identical with Splienolepis leurriana 

 (Dunker) Schenk, although the cones ascribed to the former differ 

 from those of the latter. Heer notes the resemblance between the 

 remains of foliage of Cyparissidium, Widdringtonites, Glyptostrobus, 

 Artlirotaxis, and Sequoia. 



Araucarites hamatus Trautschold, which Seward 3 doubtfully 

 includes in the synonymy, is here excluded. There is some sugges- 

 tion of Splienolepis in Trautschold's figures, but not enough for cer- 

 tainty. These figures are, however, almost identical with the conif- 

 erous twigs from Glen Rose, Texas, which Fontaine describes as 

 Sequoia pagiopliyMoides new species. 



The species may be a composite one; its wide geographical and 

 geological range offers some basis for such a suspicion, but the mate- 

 rials available for study do not furnish reliable data for its segregation. 



Occurrence. — Patuxent formation: New Reservoir, Ivy City, 

 District of Columbia; Fredericksburg, Potomac Run, Trents Reach, 

 Dutch Gap, Telegraph Station (Lorton), Cockpit Point, Kankeys, 



i Heer, Flora foss. Arct., vol. 1, 1808, p. 83, pi. 43, figs. If,/, g, 3c. 



2 Heer, Contrib. Flora foss. Port., vol. 3, pt. 2, 1874, p. 74, pi. 17, fig. 5b, c; pi. 19; pi. 20. fig. If; pi. 21, 

 figs. 96, lOeZ. 

 s Wealden Flora. 





