(io 5 ) 



5- or 6-angled, 16-30 p, with pronounced trigones, cuticle 

 smooth or very slightly roughened. (Plate 14.) 



On rocks, Crater Lake, at foot of Chilcoot Pass, altitude 

 about 900 m., May 24, 1898. Although Mr. Williams' speci- 

 men is wholly sterile, the peculiarities of the species are so 

 striking that we think our description and figures will make 

 possible its easy recognition. We are unacquainted with any 

 Scapania which seems closely related to this species. Sca- 

 ■pania Kaiirini Ryan, from Norway, has obtuse, entire or 

 subentire leaf-lobes but here the resemblance ceases, for 

 S. Kaiirini is a much smaller plant in every way, its leaves 

 increase in size toward the stem-apex, are commonly sub- 

 vertical, and are less deeply lobed, the dorsal lobes are not at 

 all imbricate unless at the very apex of the stem, the ventral 

 lobes are ovate or obovate, the root-hairs are numerous, etc. 

 The arrangement of the leaf-lobes in Scafiania imbricata is 

 quite suggestive of the genus Diflophylleia, yet the plant is 

 doubtless a true Scafiania. 



Explanation of Plate 14. 



Figs, i and 2. Stems (secondary), natural size. 



Fig. 3. From near base of stem, dorsal view, X 7- 



Fig. 4. Apical portion, dorsal view, X 7- 



Figs. 5 and 6. Portions of stem with typical leaves, dorsal view, X I2 - 



Figs. 7 and 8. Same portions, ventral view, X I2 - 



Figs. 9 and 10. Single leaves viewed from outer (lower) surface, X I2 - 



Fig. 11. Leaf cells from apex of ventral lobe, showing margin, X 2 45- 



Fig. 12. Leaf-cells from middle of ventral lobe, X 2 45- 



Fig. 13. Cross-section of (secondary) stem, X 4°- 



Fig. 14. Cells from near surface in cross-section of (secondary) stem, X 



245- 



2. An Enumeration of the Mosses collected. 



By R. S. Wiuiams. 



Our party arrived at Dyea, Alaska, March 23, 1898, and a 

 day or two later a few specimens of mosses were collected in 

 the immediate vicinity, from which time on collections were 

 made at intervals as opportunity offered till Dawson was 

 reached on the 21st of June. On our arrival the streets of 



