NOTES ON THE MARINE FAUNA OF ISLAND BAY, 

 WELLINGTON. 



Between the tide-marks are many sheltered rock-pools, and in 

 these are small fish, crabs, and a few interesting seaweeds. On the 

 margins of these pools and in clefts of the rock there frequently occur 

 the spirally coiled egg-masses of the large Siphonaria obliquata and 

 of the two common limpets Cellana radians and C. ornatus. As these 

 egg-masses become older many diatoms are found in them, and certain 

 Gymnomyxa, notably Amoeba agilis. As the masses deliquesce they 

 shelter a Vorticella, which, although marine, has a contractile vacuole. 

 In addition to the pools there are many guts or chasms in the rock, 

 and here there is abundance of life. The brown seaweed Lessonia 

 variegata, with its buttress-like base, gives shelter to Annelids, Crus- 

 tacea, and many sponges, especially Calcarea. Among the last are 

 Syconute dendyi and the striking Grantessa intus-articulata. On the 

 leaves and stems of the Lessonia are frequently found anemones, 

 Sagartia nutrix and others, as well as several gastropods, noticeably 

 the beautiful little Cantharidus dilatatus and the larger Cantharidus 

 opalus. The stems are often bored by Polychaetes. 



In the more sheltered pools is an abundant growth of coralline 

 seaweeds, and if the masses be pulled apart they are often found to 

 shelter Dolichoglossus otagoensis. This animal is from i in. to i^in. 

 in length, and of a bright-red colour. It is allied to a Japanese 

 species. The same seaweed shelters many young sand-stars and small 

 sponges and Tunicates, many developing Crustacea, and worms. These 

 masses form the nursery of the rock-pool fauna. 



Beneath the stones are several interesting molluscs, as, for ex- 

 ample, the small A cmaea fr agilis and the great Scutus ambiguus, whose 

 flattened white shell is concealed by the spacious mantle-folds, the 

 whole surface, except the sole of the foot, a deep blue-black. Three 

 species of Haliotis are found. The older specimens of H. iris and 

 H. australis forsake the shelter of the stones. H. iris, coming down 

 from Miocene times, is the paua of the Maori. He formerly used the 

 animal as food, and the shell to form the eyes of gigantic carved 

 figures. Fully exposed upon the rocks, often well above high- water 

 mark, are two species of Melaraphe, allies of the European periwinkle 

 (Littorina). Much less exposed, and often seeking shade, are two 

 species of Onchidella. 



The large Holothurian, Stichopus mollis, is abundant, and exposes 

 itself freely where the sea-floor is sheltered. Under stones and in the 

 sand smaller Holothurians are found. The starfish that is most 

 abundant is the small, pentagonal Asterina regularis, usually blue, 

 but not infrequently yellow or green. Of other starfishes that occur 

 here the largest and handsomest is Asterias scabra, usually blue above 

 and with red tube - feet. The only known specimen (now in the 

 Victoria College museum) of the remarkable monotypic genus Eury- 

 gonias (E. hylacanthus] was found at Island Bay. 



Of Ophiuroidea, the common sand-star Ophionereis schayeri occurs 

 in abundance under stones. The large brittle-star, Pectinura maculata, 

 abundant in some parts of New Zealand, occurs occasionally here. 



