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 quadrata Hymenostylium curvtrostre 
Pellia Fabroniana Tortella tortuosa 
Lophozia badensis Encalypta contorta 
Lophocolea minor Mnium orthorrhynchum 
Cololejeunea Biddlecomiae  Plagiopus Oedert 
Frullania riparia Myurella julacea 
Saelania glaucescens Amblystegiella sien 
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 Racomitrium aciculare 
Scapania nemorosa Ulota americana 
Scapania undulata Pterigynandrum filiforme 
Radula obconica Brachythecium plumosum 
Andreaea petrophila Sematophyllum carolinianum 
Andreaea Rothit Hygrohypnum dilatatum 
Rhabdoweisia denticulata Hygrohypnum eugyrvum 
Dicranum fuloum 
