-65- 



Fig. 4. Shows a single joint of a tooth ; a is the deposit laid down on the 



dorsal wall of the cell, and b shows the deposit made on the inside. 

 Fig. 5. Shows the deposit laid down on both sides of one of the bottom (or 



top) walls of these cells at b, and of the external deposit at a. 

 The inner wall of the peristomial layer becomes thickened on either side of 

 the keel line forming the segments of the inner peristome, while the inter- 

 mediate cell walls of the other cells just inside the peristomial layer forms 

 the cilia. 



The number of these cells adjoining each cell of the peristomial layer is 

 somewhat variable, consequently, as is well known , the num ber of cilia between 

 the segments often varies in the capsule (See also Fig. 15, Plate i). Some- 

 times not only the vertical cell wall becomes thickened but the transverse 

 junction also, when the cilia become appendiculate. The separation of 

 teeth and segments, as well as the separation of tooth from tooth and seg 

 ment from cilium, is brought about by the absorption or breaking down of 

 the connecting portions of the cell walls. In some degenerate peristomes as 

 in the the case of Pylaisia intricata, P. 7/<?/z//z;z^z and ^Burnettia {Homalothe- 

 cium) subcapillatum the walls connecting inner and outer peristomes 

 remain, so that the two never become separate. 



♦Named in honor of the late D. A. Burnett. 



THE MOSSES OF ALASKA. 



By J. Cardot and I. Theriot 

 From "Papers from the Harriman Alaska Expedition." 

 (Continued.) 

 Enthosthodon spathulifolius Card, and Ther. 



Polygamous, rather densely caespitose, green above, brown within. 

 Stem erect, 10-15 mm. high, radiculose, branching with slender clavate 

 branches, starting beneath the parichsetium. Leaves soft erect-appressed 

 when dry, sometimes subcrispate, spreading when moist, the lower minute, 

 ovate, the upper larger, 1.5-2 mm. long, i broad, oblong-spathulate, entire, 

 obtuse or subapiculate, margins plane, sometimes subrevolute towards the 

 base; costa thin, attenuate, vanishing not far from the apex; areolation lax, 

 basal cells subrectangular, 60-80 by 30//, median and upper shorter, rectan- 

 gular, quadrate or subhexagonal, 25-30/^ long, 20 broad, the marginal cells 

 often longer and narrower. Flowers polygamous, terminal, sometimes uni- 

 sexual, sometimes synoicous : antheridial buds growing at the tip of the 

 branches. Capsule on a pale yellow flexuous seta 6-9 mm. long, obliquely 

 erect, pyriform with a distinct attenuate neck ; operculum convex mammil- 

 late. Calyptra short-cucullate, not at all or scarcely inflated. Other char- 

 acters unknown. 



From St. Paul Island (Trelease, 2067, 2074). 

 A remarkable species, very distinct from all the Enthostodon of Europe 

 and North America by its polygamous inflorescence, its leaves shortly spatu- 



