32 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



abruptly to a height of several hundred feet above the sur- 

 rounding plain. Geologically, these ridges are a part of the 

 Central Lowland. From an ecological standpoint, however, 

 they conform with the Highlands. The Eastern and Western 

 Highlands are made up for the most part of a complex series 

 of crystalline rocks — gneisses, schists, and granites. The 

 forces of erosion, acting on these, have produced an uneven 

 and rugged topography. Like the trap ridges, this region is 

 well wooded, and, while on the whole unsuitable for agriculture, 

 it exhibits a diversity of conditions, and is characterized by a 

 rich bryophytic flora. 



From a bryological standpoint, the most interesting isolated 

 formation in the state is the Stockbridge limestone, which 

 covers the greater part of the towns of Salisbury and Canaan, 

 extending southward through the Housatonic Valley more or 

 less continuously to Ridgefield. A few species grow in this 

 region which have been collected nowhere else in the state, 

 viz.: 



Lophosia Muelleri Amhlystegiella confervoides 



Barbula fallax Amblystegium noterophilum 



Thuidium abietinum Cratoneuron filicinum 



Other species occur here which, although characteristic of 

 limestone regions, are found in other localities growing on 

 serpentine or other rocks, e. g. : 



Preissia quadrat a Scolania glaucescens 



Frullania riparia Hymenostylium curvirostre 



Fissidens cristatus Myurella gracilis 



Chrysohypnum stellatum 



The distribution of the Bryophytes is somewhat restricted 

 and frequently the habit of the individual plant greatly modified 

 by differences of Hght and shade. In a general way two 

 rather broadly defined classes may be recognized : light-loving, 

 and shade-loving Bryophytes. In the first of these classes 

 may be placed such species as — 



Riccia arvensis Tortula papulosa 



Frullania eboracensis Bryum argenteum 

 Anthoceros levis Thelia Lescurii 



