260 THE POTOMAC OR YOUNGER MESOZOIC FLOEA. 



stout short twigs, oblong in form, with woody or leathery scales wedge-shaped 

 and truncate on the free surface, strongly divergent when mature; male 

 aments? narrowly oblong-elongate, persistent, composed of thin, ovate, 

 imbricated scales, terminal at the ends of short slender lateral twigs. 



Locality: 72d mile-post, near Brooke. 



This plant is rather common at the above-named locality. In the 

 character of the cones it is somewhat like Athrotaxopsis, but unlike that 

 genus the scales opened widely on ripening. The leaves also are unlike 

 those of Athrotaxopsis. The male aments given at {(i) seem to be persist- 

 ent, for they remain on branches that show the ripened cones. They 

 show open chaffy scales. The plant is not uncommon at the 72d mile- 

 post, but very rarely shows cones, and is a good deal like Sphenolepidlum 

 Kurrianum Heer (Sphenolepis Kurrkma Schenk), but the cones are not 

 globose. 



Sphenolepidium Kurrianum, Heer. 



Plate CXXVI, Figs. 1, 5, 6; Plate CXXVIII, Figs. 1, 7 ; Plate CXXIX, Figs. 1, 4, (i, 8; Plate CXXX, 

 Fig. 11 ; Plate CXXXI, Fig. 4 ; Plate CLXVII, Fig. 2. 



Twigs branching copiously, often much crowded, ultimate twigs rather 

 short and rigid, going off very obliquely and tending to assume a fastigiate 

 grouping; leaves imbricated, scale-shaped, the facial ones close appressed, 

 elliptical or oblong, subacute, lateral ones oblong or ovate-acute, often 

 with the tips spreading and incurved, decurrent, lateral and facial, leaves 

 keeled on the back, all usually thick and sometimes deciduous; cones not 

 seen. 



Localities : All the Dutch Gap localities, especially at the entrance 

 to Trent's Eeach and the fishing hut above the canal ; Fredericksburg ; 

 72d mile-post; bank near Brooke; near Telegraph Station. 



It is more common at the 72d mile-post than at any other place. It 

 is very abundant here in the form of small fragments. Some of the spec- 

 imens show a very copious branching and crowding of the twigs, covering 

 the shale with an intricate mass of them. Of such a character is the spec- 

 imen PI. CXXVIII, Fig. 1 from near Telegraph Station, and PI. CXXVI, 

 Fig. 1 from the 72d mile-post. This latter is a form with leaves thinner 

 and more slender than usual. In some of the other specimens, such as PI. 



