33$ CARDOT AND THERIOT 



AMBLYSTEGIUM SERPENS BERINGIANUM var. nov. 



A forma typica cliffert foliis ovato-lanceolatis latioribus brevius 

 acuminatisj costa validiore ad basin acuminis producta, cellulis basi- 

 laribus rectangulis, parietibus incrassatis. 



From St. Paul Island (Trelease, 2089 in part). 



Under number 1760 we found some stems of a stouter species, 

 much resembling A. radicale (Pal. Beauv.) Mitt. 



AMBLYSTEGIUM VARIUM ALASKANUM var. nov. 



Robustius, dense ramosum, late depresso-cespitosum, folia breviora, 

 late ovata, subito constricta, breviter et anguste acuminata, cellulis 

 alaribus inflatis, multo majoribus. 



From Muir Glacier (Trelease, 1752). 



Genus Hypnum Dill. 



Section Chrysohypnum Hpe. 



HYPNUM TRELEASEI Ren. sp. nov. 



(PL xxii, fig. 5«-«.) 



Dense cespitosum, fragile, lutescenti-viride. Caulis brevis, 2-3 

 centim. altus, erectus, inferne radiculosus, ramis erectis fastigiatis. 

 Folia conferta, parva, subimbricata, interdum subhomomalla, 1.2 

 millim. longa, 0.6 lata, ovato-lanceolata, breviuscule acuminata, vix 

 plicatula, plerumque magno augmento, prascipue basin versus, minute 

 denticulata, costa gemella brevi, cellulis basilaribus quadratis vel 

 breviter rectangulis, chlorophyllosis, externis elongatis decurrentibus, 

 caeteris linearibus, 30-40 /1 longis, 6—7 latis. Caetera ignota. 



From Virgin Bay (Trelease, 2305) ; St. Matthew Island (Trelease, 

 2158, 2165). 



The description here given, as also the drawing, is based on the St. 

 Matthew Island specimens. The Virgin Bay specimen has the leaves 

 longer, with a more elongated and narrower acumen, and a closer 

 areolation, formed of longer and narrower cells. There is, however, 

 no doubt of the specific identity of the two specimens. This species 

 should be placed near H. stellatum Schreb., from which it is distin- 

 guished by its much smaller dimensions, its short and fastigiate stems, 

 its leaves which are small, imbricate, shortly acuminate and for the 

 most part finely denticulate, and, finally, by its small, quadrate alar- 

 cells, the median ones shorter. 



