MARYLAND WEATHER SERVICE 215 



Panicum depauperation 

 Linum medium 

 Antennaria plantaginifolia 

 Solidago virgata 

 Veronica officinalis 

 Kneiffia fruticosa 

 Houstonia coerulea 

 Senecio balsamitac 

 Tn linum terefifoUum. 



The contrast between the thin Serpentine soils just described 

 and the deeper Conowingo clay has been noted near Conowingo, 

 Cecil County. At a locality where a cut in the county road shows 

 the soil to have a depth of five feet, there is a forest stand made 

 up of Chestnut, Black Oak and White Oak, together forming 80% 

 of the stand, in which the Black Jack and Post Oaks fall in abun- 

 dance so as to make together only 5% of the total. The Pignut Hick- 

 ory, the Sassafras and the Black Gum are present in small num- 

 bers. Not only the arboreal but the shrubby and herbaceous floras 

 as well here partake of the character of Loam topland. 



Vegetation of the Susquehanna Gravel. 



The Gravel soils of the type which has been designated as Sus- 

 quehanna gravel by the Soil Survey, are deposits mainly of Cre- 

 taceous but partly of Pleistocene age, which are sometimes of con- 

 siderable depth. They are irregularly distributed along the south- 

 eastern edge of the Lower Midland District, occurring in a belt of 

 country about ten miles in width just within the "Fall-line." The 

 farthest areas from the "Fall-line" are shallow deposits overlying 

 granite and gneiss and are confined to the topland or level hilltops. 

 Nearer the "Fall-line" more extensive areas occur, which are more 

 varied in their topography, comprising abrupt isolated hills, such 

 as Foy's Hill and Egg Hill in Cecil County, as well as level areas 

 and ravine bottoms. The topography is much younger and more 

 irregular than that in the Piedmont Plateau proper. The Neck 

 lying between the Elk and North-East rivers, while technically a 



