OLIVER.— Marine Littoral Plant and Animal Communities. 537 
portion of this intertidal platform contains a remarkable collection of 
patelloid molluscs associated with immense numbers of Melaraphe of two 
species. All the crevices and water-channels are filled with molluses. Three 
species of Cellana are almost equally common and mixed together, though 
they segregate to a certain extent. The shells are not badly eroded, though 
the apexes of the larger examples are seldom perfect. C. strigilis attains 
a length of 67 mm., C. radians of 51 mm., and C. ornata 47mm. With 
these are associated equally plentifully Siphonaria obliquata (65 mm.), 
Sypharochiton pellisserpentis, and Siphonaria zealandica (23 mm.). S. obli- 
quata occurs in clusters of fifteen to thirty, the shells often overlapping, 
on rocks fringing pools. Under water on the bottoms and sides of pools 
they deposit their ribbon-like spawn in large numbers. Each takes the 
along with that of S. obliquata. Melaraphe unifasc n cincta occur 
immense numbers, sometimes densely clustered together. High up on 
the rocks Notoac pileopsis (26 mm.) occurs with М. cincta 20 mm 
Shells of N. pileopsis are perfect, but those of M. cincta are widely and often 
deeply eroded. Other molluscs, collected chiefly under stones, were Mono- 
donta nigerrima, M. coracina (diam. 1 .) 
dala; while N. parviconoidea was found on the rocks. Piles of seaweed 
are washed up everywhere, and emit a considerable smell. On Macrocystis 
shells padok, others with the black outer layer almost entirely removed, 
showing the nacreous layer below. Algae take but a small part in the 
Cellana-Melaraphe association. A Corallina with whitish fronds in some 
of the pools, and small tufts of Ulva on the rocks, were all that were 
noticed. 
Cellana-Nerita Association. 
Little Barrier Island.—The rocks here are for the most part large lava 
boulders. At one point the breccia of the cliffs is hard and compact enough 
to withstand the surf, and here the association is perhaps best developed. 
The dominant species are Cellana radians (40 mm., alt. 10 mm.) and Nerita 
melanotragus. With these are associated commonly Monodonta aethiops, 
M. atrovirens (diam. 27 mm.), Turbo smaragdus, Sypharochiton pellisserpentis, 
formis, N. parviconoidea, and Patelloida stella corticata. Under stones occu 
and Actinia tenebrosa. 
Atalacmea unguis-almae, Monodonta lugubris, 
Melaraphe Association. 
Peninsula.—The rock here is hard volcanic, 
ches highest above tide-marks. Only 
ted. Bo 
ells are elongated ; 
Associated with Melaraphe, but not reaching 
