April, 1917. The Queensland Naturalist. 57 
The fauna includes Hemitoma, Drupa, Cellana, Thais, 
Ostrea, Liolophura, and small forms of Tetraclita rosea. The 
region is, perhaps, best regarded as being the upper portion 
of the Sargassum zone. 
B. Tetraclita — Liolophura horizon.— T)T\s is characterised 
by the presence in abundance of the pinkish four-valved 
barnacle Tetraclita rosea and the chiton Liolophura queens- 
landica. The former is especially common on the cliff face, 
exposed to the dashing surf, and reaches its maximum 
development in this zone, though it occurs lower down also. 
It may form a ver}’’ definite pinkish-white band on the rocks 
facing the sea. It is able to withstand the sun's heat and 
drying for many hours each day, and can live out of water 
for several days. Other members of the fauna are Drupa 
marginalba, Bemhicium melanostoma (in sheltered situations, 
and extending upwards into the next zone), Siphonaria 
sCiihra, Cellana variegata, Ostrea cucullata, Tetraclita pur- 
purascens (in cracks between rocks and under ledges), the 
anemones Oiilactis muscosa (in cracks and shallow gutters), 
and Paractis papaver (under rocks and ledges). . 
The chief plant is Entermorpha intestinalis , with Viva 
and Ceramium occasionally.. 
C. C.hthamalus horizon [lower Melaraphe zone). — The 
dominant organism here is a small, fiat, six-valved barnacle 
Chthamalus antemiatus, whose greatest development occurs 
immediately above the limits of Tetraclita rosea. It is gener- 
ally coloured exactly like the rock surface on which it is 
situated. There is usually little evident vegetation in this 
zone wliich is submerged only dunng spring tides. Stunted 
narrow Enieromorpha may be present. 
The fauna includes Cellana variegata, Bemhicium melano- 
stoma, Melaraphe unifasciata, M. infans, M. acutispira, 
M. melanacme, with Tetraclita purpurascens and Paractis 
papaver in sheltered situations. Siphonaria sometimes 
reaches this horizon. None of these are characteristic of 
the region as they attain their best development either above 
or below it. Owing to the abundance of littorinids, T consider 
that the name lower Melaraphe zone would be equally 
applicable, though the name Chthamalus zone is more dis- 
tinctive since the barnacle has a much more restricted range. 
The latter reaches its maximum development only in exposed 
situations, Melaraphe spp. invading the horizon in more 
sheltered spots. 
D. Melaraphe zone [upper Melaraphe zone). — The name 
is here applied strictly to that horizon where species of 
Melaraphe are the dominant, and almost the only forms of 
animal life. Though abundant in the last zone, they reach 
