INTRODUCTION TO THE MOLLUSCA. v 



Chitonelli, which slide rapidly away or conceal themselves in holes. In every part where 

 solid rock was seen the bright blue gills of the Iridacna were visible in the fissures, while 

 Neritee and Patella covered the stones along the shore. As soon as the tide rose and 

 bathed the rocks, Conies and Balani that encrust them exhibited a strange appearance, 

 millions of branchiated feet being then extruded from the apertures of their shells, all 

 vibrating at once in a regular measured manner, and forming little vortices around them ; 

 various Gastropods, now beginning to feel the water welling up around them, would be 

 seen to dilate their locomotive discs, exsert their siphons, and cautiously forsake the holes 

 and crevices where they had lain concealed ; while on the sandy patches the siphons of the 

 Sole?i and the Mactra were protruded from innumerable holes, starring the soil with their 

 beautiful fimbriated extremities. At Manado, another part of the coast of Celebes, the 

 coast line is very different, and seems to consist of the side of a volcanic mountain, the 

 anchorage, at the distance of a mile from the shore, being in 150 fathoms, with a floor 

 composed of iron-stone sand. In the fresh-water ponds and rivulets Auricula subulata and 

 Conovulus leucoclon were found upon the moist banks in company with species of Assiminea, 

 and on the mud-flats of the river, during the reflux of the tide, myriads of Clithon, Neritincs, 

 and MelanicB were observed ; while Pirence were numerous in the bed of the river, where 

 the water was deeper. The Neritina sulcata was found on the foliage of tall trees, many 

 hundred yards from the river. Neritincs and Navicellce were obtained from floating sticks, 

 and from the petioles and roots of the Nipah palm ; while Ampullarice were not uncommon 

 in the still ponds, many being observed on the stones out of the water. The shores of the 

 volcanic island of Gillolo, and others of the Molucca Archipelago, with arms separated by 

 narrow channels of the sea, surrounded by barrier reefs and coral fringes, abound with 

 molluscous animals. On some of the shallow shores, especially where there were no currents, 

 the water was appreciably warm, averaging about 84° Fahr., whereas throughout the ocean 

 generally it is usually about 39° Fahr. Among these islands, as elsewhere, we found 

 herbivorous mollusca, that feed upon the Algce and Fuci covering the rocks and stones : — 

 Purpura, Littorina, and Nerita on exposed rocks, Chiton and Boris, Patella, Siphonaria, 

 and Vermetus adhering to the stones, with Mytilus, Ostrcea, and Byssoarca anchored in 

 the clefts. A little further out, the Naticce and Olives, partly covered by then foot, form 

 burrows in the sand in company with Nassa and Pyramiclella, while Verms, Solen, and the- 



