[293] HEPATIC^E OF ALASKA 347 



Pallavicinia hibernica differs from P. lyellii, which is rather com- 

 mon in eastern America, in having in the midrib no central strand 

 composed of elongated thick-walled cells. This difference places it in 

 the subgenus Mcerckia, which is regarded as a distinct genus by sev- 

 eral European writers. Its closest ally is P. blyttii (Morck) Lindb., 

 a widely distributed European species, which may be expected also in 

 northern America. P. hibernica differs from this species in its smaller 

 size, in its white and not yellow rhizoids, in the comparatively broader 

 unistratose wings of its thallus, in the sharper points on the divisions 

 of its $ and 9 scales, and in its spores, which are not tuberculate- 

 spinose. 



6. Pellia endiviaefolia (Dicks.) Dumort. 

 Yakutat (Saunders). New to Alaska. 



7. Pellia neesiana (Gottsche) Limpr. 



Douglas Island (T. 1418, in part) ; Juneau (Saunders 1420) ; 

 Port Wells (T. 1430, in part) ; Orca (T. 14250) ; Yakutat (T. 1440). 

 New to Alaska. 



Many other sterile specimens of Pellia occur in the collection, but 

 cannot be determined. It is probable that some of them are P. epi- 

 phylla (L.) Corda, which has been recorded by Miss Cooley from 

 Salmon Creek, Sitka, and which is also mentioned by Professor 

 Campbell 1 as abundant in Alaska. 



8. Blasia pusilla L. 



Juneau (T. 1421). New to Alaska. 



Two species of Metzgeria have also been recorded from Alaska : 

 M. hamata Lindb., collected by Miss Cooley at Gold Creek near 

 Juneau, and M. pubescens (Schrad.) Raddi, collected by Miss Cooley 

 in the same locality and also by the Drs. Krause at Chilcoot. Dr. 

 Trelease's 2355 from Sitka, is a species of this genus, but is sterile 

 and gemmiparous, and cannot be clearly identified. 



JUNGERMANNIACE.E. 



9. Gymnomitrium obtusum (Lindb.) Pears. Journ. Bot. 18:337. 



1880. 

 Cesia obtusa LINDB. Medd. Soc. F. et Fl. Fenn. 3 : 190. 1878. 



Dioicous : densely caespitose or scattered among other bryophytes, 

 pale glaucous-green throughout, or at the tips of the stems and 

 branches, brighter green and sometimes tinged with brownish or red- 



Amer. Nat. 33: 397. 1899. 



