1900] OBSERVATIONS ON LESSONIA 319 
below it presents in places an almost smooth fixation area, 
rounded off and mottled by the superposition of and compres- 
sion together of the different hapteric branches. This generally 
bulbous base is irregular on one side, where a protruding corner 
ofrock had entered it, and is hollow, indicating that many of 
the hapteric branches were turned under the base of the stem. 
The main stipe can scarcely be distinguished from the hold- 
fast by which its lower portion has been overgrown. Of the 
seven branches which arise the largest is 3.5°" in diameter, while 
the smallest is 6™™. All of these appear to be about the same 
age, and all are strongly fenestrate near the base. This, I pre- 
sume, may be due to the growth of epiphytic animals and vege- 
lation. The whole base of the plant is covered with a growth 
of bryozoans, together with Cladophora, Rhodymenia, and other 
alge, while barnacles and sertularian hydroid colonies are grow- 
mthe lacunae. It is to the growth of some of these organisms 
that Iam inclined to attribute the lattice-like and hollow char- 
aes the stipe area near the base. Similar pathological pet 
forations and lacunae are found on distal regions, but not so 
abundantly, For the most part the more distal portions of the 
“tipe are solid, as in the tribe Lessoniex generally. Toward the 
-_* or is cylindrical, but it becomes flattened — 
aaa above the holdfast, cylindrical branches 12 sa 
_ tare developed. Along the same branch system 10 
3 lr » the stipe is 12™™ by 8™™ in transection. Distally 8° of 
ae on the same branch system, the flattening is stronger and 
ions 15™™ by 4mm are found, while the terminal portions of 
as which give rise to the separate laminae may be but 2 oF 
| Ot is and 20™™ in breadth. The branching through: 
: “nope and the paired laminae are ordinarily 8 
lamina of four at the tips of the flattened apie seis 
times ¢ : ony — be called a petiolate base, and pe : ome 
‘ a tical in cross section, though more often ] ad 
Slight a color = the stipe and holdfast is brown, fe a 
Me lassi, ge the tint persists beyond the petioles of the amine. 
® themselves are lighter in tint, becoming quite green 
