Outtver.—Marine Littoral Plant and Animal Communities. 535 
Chamaesipho Association. 
Wellington Harbowr.—At Worser Bay а sessile-barnacle formation 
occupies a belt of rocks about 1j m. in vertical width stretching between 
high- and low-water levels, neap tides. Above there is nothing on the 
rocks save Melaraphe ; below is a brown-algae formation. The rocks are 
fairly well covered with young Chamaesipho columna. It occurs in patches 
of varying extent, and is 2mm. to 3mm. tall. en growing close 
together the shells are narrow and tall, hence the columnar appearance. 
Besides Chamaesipho, fixed animals occur only in crevices.. Here are 
a few specimens of Elminius plicatus, abundance of Vermilia carinifera, 
ac 
the Chamaesipho are a number of molluscs. Along the upper border 
Notoacmea pileopsis is common enough. Thickly scattered about through- 
out the association are Risellopsis varia and Lepsiella scobina, and, in the 
upper portion, Melaraphe unifasciata and М. ci П. Cellana 
radians and Sypharochiton pellisserpentis are abundant and conspicuous, 
the shells often supporting Chamaesipho columna and Notoacmea parvi- 
conoidea, and showing a considerable amount of erosion. — Monodonta 
aethiops and M. coracina are common. They are most in evidence while 
covered by water, retiring to crevices and under stones as the tide ebbs. 
Other molluscs are Cellana ornata, C. denticulata, Onchidella, Haustrum 
haustrum, Siphonaria zealandica, Turbo smaragdus (on Codium), Monodonta 
l 18. 
uranga.—On the North Rocks of Mount Maunganui, in the mid- 
tide belt, a sessile-barnacle formation is well developed. The lower 
ortion of that belt immediately above the Corallina association 18 
characterized by the rocks being almost. a covered wit small 
imen } n 
following molluses, a | 
: is, Haustrum haustrum, Monodonta aethiops, M . atrovirens, 
Lepsiella scobina, and Nerita melanotragus, all with the apex more or less 
eroded, in which respect Nerita is the most resistant. Also occurring m 
this association are Elminius plicatus, patches of Vermilia carinifera, and 
the erustaceous brown alga Leathesia. 
rock-pools the life 2 a little different. There is a certain amount 
of protection from the surf, and no daily exposure to the air. Elminius 
is absent, but the following animals were noticed : Ostrea cucullata (rare), 
Turbo smaragdus, Cominella virgata, Cerithidea subcarinata, Patiriella regularis, 
inus chloroticus. : 
era the UTE portion of the association large specimens of Chamaesipho 
columna are the dominant forms. The shells are characterized by projecting 
horizontal laminae, possibly showing growth-stages. Associated with this 
species are Cellama ornata, Siponaria zealandica, pens ay = 
N. parviconoidea, Patelloidea stella, Nerita melanotragus, on ~ өз 
virens, Elminius plicatus (with Chamaesipho columna ce ed), "s : 
especially along the upper border, Melaraphe unifasciata. In shady places 
