35 
(worm tubes), the minute bivalved shell, Halobia 
hochstetteri and the comparatively large mussel, 
Mytilus problematicus. Other Triassic shells 
exhibited here are the striking lamp-shell, Hectoria 
bisulcata , the bivalved Myophoria, and the slit- 
band snail, Pleurotomaria. 
Fig. 37. A Triassic Bivalved Shell from New Zealand — 
Pseudomonoiis richmondiana (Zittel). 
The Silurian fauna is contained in the Wangapeka 
series of Reefton, including the corals, Favosites and 
Pleurodictyum ; crinoids, lamp-shells as Orbic- 
uloidea ; a large form of Orthothetes, Chonetes, 
Orthis, and Spirifer ; the bivalved molluscs, 
Grammysia, Palaeoneilo and Actinopteria ; 
the cephalopod, Orthoceras; and the trilobite 
Homalonotus. 
