Proceedings and Collections. 



rare, or if it has not been observed in more than tw 

 three stations, the stations are recorded, otherwise "com- 

 mon," "frequent" or other expressions t<> indicate abund 

 are used. (3) All statements of localities, for a Bpecies 01 < ' 

 its abundance, not followed by any name of a person, are 

 based on the writer's own observations or collections. (4 I 

 the name of a person follows any statement in the same 

 sentence with it, it indicates that such person alone is au- 

 thority for the statement. (5) References are frequently made 

 to specimens in collections because such evidence is of the 

 first importance. I would strongly urge every botanist of 

 the vallej- to hereafter press all plants collected (certainly all 

 those which are supposed to be at all rare), and place dupli- 

 cates of them in the general herbarium of the Institute, for 

 the use of future workers on the geographical distribution of 

 species. 



Geologically the Lackawanna and Wyoming form one 

 long, closed valley, and its mountain-walls gradually coalesce 

 at each end to become a single range. Because of the south- 

 eastern curvature of both of these ranges,— the Moosic on 

 the southeast and the Lackawanna on the northwest,— it 

 presents, on the map, almost the form of a crescent. Through 

 the walls of Lackawanna Mountain the Susquehanna River 

 has broken, and passes into the valley at Campbell's Ledge ; 

 then out of it, skirting the precipitous base of the River 

 Mountain ; then quite across the valle}' at Mocanaqua, and 

 out again. This affords bold cliffs near a river, always favor- 

 ite haunts of rare plants. Campbell's Ledge, above Pittston, 

 at the upper gateway of the Susquehanna, rises abruptly 760 

 feet above the river, and over 1300 feet above tide. We find 

 the Walking Leaf Fern and the Cliff Brake {Pcllcta atro}mr- 

 2>urea) on its summit, together with a rare flax (Linum su'- 

 catum), and a still rarer grass (Kceleria cristata). The latter 

 also occurs on the River Mountains. Several miles northeast- 

 ward from Campbell's Ledge occurs the highest point of the 

 Lackawanna range — Bald Mountain. It is easily reached by 

 a good mountain-road from Scranton, and has an elevation of 

 2385 feet above tide. On its bold parapets of conglomerate 



