No. 11.] THE BRYOPHYTES OF CONNECTICUT. 79 
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22. 
23. 
24. 
25, 
26. 
27. 
28. 
29. 
30. 
Chlorophyll cells trapezoidal in cross section; the walls 
not thickened, and the broad base toward: the outer 
surface of the leaf; hyaline cells strongly convex toward 
thes iter SUPLACE: . osoceeceis ccs pares eecelerdip sieceuncase S. dasyphyllum 
Chlorophyll cells barrel-shaped to rectangular in cross 
section, equally free toward both surfaces, and with the 
free walls usually thickened ............. 0. cc cece eee 23 
Cortex of stem consisting of 2-several layers of cells.... 24 
Cortex of stem consisting of one layer of cells........... 25 
Stem leaves small, not more than 1 mm. long, fibrils 
present only. near the apex; branch leaves secund.... 
S. contortum 
Stem leaves larger, 1.5-2 mm. long, fibrils usually abundant 
throughout; branch leaves not secund...... S. platyphyllum 
Branch leaves with many pores, at least on the outer 
surface; pores frequently in bead-like rows............ 26 
Branch leaves with very few or no pores............ S. obesum 
Pores few or lacking on the inner surface.............+4- 27 
Pores numerous on both surfaces, especially on the outer; 
stem leaves I-2 mm. long.............-..2-+--- S. rufescens 
Stem leaves less than 1 mm. long, hyaline cells rarely 
SODLALer a cccwariraatvatau-aw sta tare waeiaeetome eens S. subsecundum, 
Stem leaves I-1.5 mm. long, hyaline cells often septate 
S. inundatum 
Chlorophyll cells of Branch leaves usually free toward 
both surfaces of the LOBES aces Sconces Sscuertnnreracne ae Spree 29 
Chlorophyll cells of branch leaves enclosed by the hyaline 
cells, equidistant from both surfaces of the ‘leaf, and 
elliptical in cross section; hyaline cells smooth or 
faintly papillose on the lateral walls....:....... S. medium 
Chlorophyll cells triangular or trapezoidal in cross section, 
the base toward the inner surface of the leaf and not 
thickened; hyaline cells strongly convex toward the 
OUTER UPTA CEE wesicd ore ia esiee cen; siasbepnd: siercuesa td svesekavniasasedbnaeaiesouabarane 30 
Chlorophyll cells more or less elliptical in cross section, 
cell cavity almost central, and both surface walls 
strongly thickened; hyaline cells more strongly convex 
toward the outer surface of the leaf than toward the 
inner surface, and papillose on the lateral walls...... 
e S. papillosum 
Chlorophyll cells broadly triangular to trapezoidal; hyaline 
cells with irregular bands of thickening on the lateral 
WALLS, sss cx copsy asaeney ac eannietsoe sm sgiasredne ole aechsntasasaasiadauaraten' a S. imbricatum 
Chlorophyll cells Hartowly triangular; hyaline cells smooth 
on: the: lateral wallsiss 3 co scsscis secur geussiscnaad 8aes S. cymbifolium 
