PRIONITIS 175 
wartlike excrescences belonging to a parasitic red alga (Lobocolax 
deformans) and no. 144, in particular, has the One of en 
deformed by this endo- sp Adis This Lobocolax i is d n SRA what 
Montagne refers toin‘ arsis (an stat 
productis?).” Some of the кирә show іп айе а. to Ше Lobo- 
colax small verrucae or papillae, especially near the base, which 
appear to be excrescences of the plant itself, due, perhaps, in part, 
to irritation caused by the presence of less conspicuous endophytes 
and epiphytes. 
The tetrasporangia in Prionitis have been supposed to be 
confined to special lateral branchlets, but in this Peruvian species 
they occur as frequently on the main segments or axes of the 
thallus, though sometimes on both the main axes and the lateral 
branchlets. However, they occur in nemathecia of more or less 
definite form, which is probably sufficient ground for allowing the 
species to remain in Prionitis, with most of the species of which it 
agrees essentially in consistency of thallus and general habit, even 
though lateral pinnae are sometimes nearly or altogether wanting. 
In the Prionitis Lyallii (P. Andersoniana) of the Pacific Coast of 
North America, the tetrasporangia may occur on small more or less 
specialized fertile pinnae or on broad chiefly vegetative pinnae. 
Antheridia and cystocarps, like the tetrasporangia, are found 
on the main axes of P. decipiens as well as upon the lateral branch- 
lets. The antheridia, so far as observed, are found more abund- 
antly on the main axes, but the cystocarps show a tendency to 
restriction to the branchlets. The antheridial sori are extensive 
and cover in places nearly the whole surface of the thallus, the 
margins often excepted. The cystocarps are 125—230 и in diam- 
eter and appear to be of the usual Grateloupioid character. 
The two specimens that we have selected for illustration repre- 
sent, perhaps unfortunately, rather extreme forms of the species. 
PLATE 64 shows (492 p.p.) an unusually luxuriant development 
of the plant, which here attains a maximum height of 70 cm., with 
pinnae sometimes 2-9 cm. long and 1.5-3 mm. wide; yet the left 
half of this same photograph shows from the same tuft less de- 
veloped plants that make a close approach to the historic type of 
the species. PLATE 65 shows (in more nearly its natural size) 
a shorter stouter plant (144 p.p.) with pinnae very irregularly 
