— 192 — 
of branchlets is almost the same in both plants, but the latter are in our 
plant much more spreading. As to the tentacula they are quite evident 
in B. Siamensis, but they seem to occur less numerously than in B. coacta. 
The joints in the different parts of the frond of B. coacta are tolerably 
equal in length, while in our plant they generally vary not inconsiderably 
in length in one and the same part of the frond. Besides the joints of 
the primary filaments of B. Siamensis are thicker than in B. coacta. 
By examination of material preserved in alcohol I can confirm the 
opinion uttered with some caution by Murray, who examined only dried 
specimens, ‘(of B. coacta), that the chromatophores agree wholly with those 
which Schmitz has described for the genus Siphonocladus. (see Engl. u. 
Prantl. Pflanzf. 1. p. 147, fig. 98). 
Koh Kahdat, in 1—2 fathoms water (coral-sand.), 
Dasycladaceae. 
Acetabularia Lamx. 
25.* A. major v. Mart. O. Asiat. Tange p. 25. t. 4; v. Solms-Lau- 
bach Acetabul. in Transact. Linn. Soc. 1895, Nr. 6. — De Toni Syll. I. p. 419. 
The splendid well developed plants agree well with this species, 
except in that the stalks are somewhat longer (up to 10 cm.) than those 
described and figured by v. Martens which difference is, I think, of 
no importance. 
The disk measures 2 cm. in diameter and the rays vary in number 
from 70 to 80. 
Abundant in the Koh Chang-Strait on rocks, stones, piles etc. between. 
tide-marks, 
Area: Siam (Simaharadscha); Timor; N. Guinea. 
Phaeophyceae. 
Fucaceae. 
Sargassum Ag. 
26. §. polycystum Ag. Syst. p. 304; De Toni Syil. Ill. p. 103. — 
S. brevifolium Grev. 
Koh Kahdat, in 1—2 fathoms water, attached to stones. 
Area: Common in the Indian and Pacific Oceans. 
Cystoseira Ag. 
27. C, latifrons Kg. Tab. phyc. X. p. 22, t. 60; De Toni Syll. Ill. p. 176. 
Perhaps the same species as C. prolifera J. Ag. 
Koh Kahdat, in 1—2 fathoms water, attached to stones. 
Area: China; Timor; Tropic. Australia. 
