﻿8 Howe: The Anthocerotaceae 



A. Carolinianus differs from A. laevis chiefly in greater size of 

 the thallus, in the longer involucres, scarcely expanded, sometimes 

 contracted, at the mouth, and in the (typically) more slender cap- 

 sules. The species as a whole is perhaps to be looked upon as an 

 aquatic or semi-aquatic analogue of A. laevis 9 fcom which it is prob- 

 ably not always distinct. It, however, departs so widely from the 

 ordinary conception of Anthoceros laevis and is usually so easily 

 recognizable that we think it has a fair claim to specific recognition. 

 Schweinitz' plant {A. laciniatus) has oblong or almost linear seg- 

 ments. The original of Michaux is not found, we are informed, 

 in his collections, now preserved at Paris. 



Anthoceros Carolinianus occidentalis var. nov. 

 Thallus usually densely caespitose, ascending, now and then 



mar 



5 X. 5-1 mm.; capsule less slender. (Plate 321.) 



On wet rocks and on the banks of rivulets near the water-line. 

 California (Underwood, Parish, McClatchie, Setchell, Jepson, Koch, 

 Howe). 



As the type of var. occidentalis we select a specimen collected 

 by Mr. W. L. Jepson, near Olema, Marin county, California, 

 April 1 , 1 893. This formed, when growing, wide cushions 3-4 cm. 

 in depth ; the margins of the frond are here but slightly or not at 

 all glandular- thickened. In drying, the thallus is not infrequently 

 much blackened. In the glandular-thickened forms, involucres 

 which seem abnormally shortened and incrassate (2-2.5 X 1 mm.) 

 are often found intermingled with the longer. Such involucres 

 commonly have scarious mouths. 



3. Anthoceros Pearsoni sp. nov. 



Thallus smooth, prostrate or ascending, rarely erect, mostly ir- 

 regularly dissected ; the major segments linear or elongate-flabelli- 



lylobed or two or 



form, 5-20 X 1-5 



three times subradiately dichotomous, plane or slightly concave, 

 rarely costate ventrally at apices, in sterile plants usually 6-11 

 cells thick, gradually or abruptly reduced to three or four at the 

 margin, in the fertile commonly expanded into a wide 3- or 2- 

 stratose lamina with a lightly crisped periphery, the lobes in both 

 often terminating in dark green, globose or difform, glandular-thick- 

 enings, .2-2 mm. in diameter, these sometimes long-peduncled, 



