Nichols: The vegetation of Connecticut 241 



tains none. Trap outcrops (diabase and basalt) occur chiefly in 

 the Central Lowland. The marble (sometimes referred to as a 

 limestone or dolomite) forms extensive deposits in the western 

 part of the state, particularly in the upper Housatonic Valley. 



Owing to their frequently intimate association with rock sur- 

 faces, no group of plants, with the possible exception of the lichens, 

 is better qualified to demonstrate the influence of the chemical 

 composition of the substratum on vegetation than the bryophytes. 

 To be sure, many mosses and liverworts apparently flourish in- 

 discriminately on any sort of rock substratum, provided only that 

 requisite conditions of moisture and shade are present. But a 

 large number of species undoubtedly "prefer" either calcareous 

 or potassic rocks, and some are confined to such substrata. A 

 list is given below of local species which favor calcareous rocks. 

 Nearly all of these are commonest in the marble areas of western 

 Connecticut, and several of them have been collected only there. 

 Some, however, occur also along the trap ranges, while a few are 

 known from other scattered localities. 



Grimaldia fragrans Cratoneuron filicinum 



Preissia qiiadrata Hymenostylium curvirostre 



Pellia Fahroniana Tortella tortiwsa 



Lophozia badensis Encalypta contorta 



Lophocolea minor Mniiim orthorrhynchum 



Cololejeunea Biddlecomiae Plagiopus Oederi 

 Frullania riparia Myiirella julacea 



Saelania glaucescens Amblystegiella confervoides 



Fissidens cristatus Amblystegium noterophilum 



The species cited in the next list are reputedly calciphobous 

 (i.e. "lime-avoiding"), and are for the most part restricted to 

 potassic rocks. 



Marsupella emarginata Glyphomitrium incurvum 



Sphenolobus exsectus Racomitriiim aciculare 



Scapania nemorosa Ulota americana 



Scapania undtdata Pterigynandrum filiforme 



Radula obconica Brachythecium plumosum 



Andreaea petrophila Seniatophyllum carolinianiim 



Andreaea Rothii Hygrohypniim dilatatum 



Rhabdoiveisia denticulata Hygrohypnum eugyriiim 



Dicranum fiilvum 



