OF SOUTH AUSTRALIA. 
319 
branched or dichotomous ; the pinnae are monosiphonous, subulate. 
Stichidia ovate, pedicellate. Twelve siphoned. 
South Australia (Investigator Strait, Eastern Bays). 
Heterosiphonia Muelleri (Sond.) De Toni. 
= Dasya Muelleri Sonder. 
Stem elongate, 30 cm. or more in length, robust, densely hairy, sub- 
dichotomous ; secondary branches very long (20 cm. to 40 cm.), much more 
slender than the stem, glabrous, corticated, simple, often naked below, 
plumose-pinnated above ; pinnae alternate, close, horizontal, subarticulate, 
pinnulate; pinnules very short, few-tubed, ramelliferous ; ramelli dichoto- 
mous, attenuated, obtuse, their articulations two to four times longer 
than broad ; cystocarps large, pedicellate, inflated, with a prominent orifice ; 
stichidia minute, linear-oblong, acute at each end. 
Attachment or holdfast, a thick, villous mass. Primary frond perennial, 
to 20 cm. or more in length, 2 mm. to 4 mm. in diameter, shaggy, with dark- 
red woolly hairs, irregularly divided, or dichotomous, its branches widely 
Fig. 154 . — Heterosiphonia Muelleri : a, plant; b, portion 
of pinnule, bearing a ceramidium; c, 
branch from the decompound (den- 
droid) placenta, bearing spores; d, a 
pair of stichidia; e, portion of ramellus. 
(After Harvey.) 
