348 Canadian Record of Science. 



becoming, as pointed out by Dana, a causative factor in the 

 growth of coral islands. 



After this hasty glance at the bottom, let us turn to the 

 shore at low tide. The edges of the key have been 

 undermined by the waves, and here in the little caves thus 

 formed, and on tbe sides of the rocks, may be seen Crusta- 

 ceans of every family, and among these, some of the large 

 and peculiar forms which render museum collections objects 

 of interest even to the scientifically uneducated. The spiny 

 lobster (Palinurus) may be observed stealthily lurking under 

 shelving rocks, below low water mark. Mollusks, the repre- 

 sentatives of many families and genera, may be found on the 

 sandy shores or attached to the rocky margins of the 

 key. Conspicuous among these are the members of the 

 peculiar Chiton family. 



The shore is strewn with the most beautiful shells, no 

 longer occupied by the animals which once carried them 

 about; many of them to be taken possession of by the 

 numerous genera of hermit crabs, which clamber over the 

 rocks. Several hundred yards from the water's edge may be 

 found a burrowing crab with powerful claws, rarely to be 

 seen in daytime, though his nightwork leaves evidence pal- 

 pable enough in the heaps of upturned sand. Not to speak of 

 numerous peculiar and beautifully colored fishes to be ob- 

 served in the coves referred to, an interesting member of 

 the Cephalopods — the poulp (Octopus) abounds in the holes 

 in the rocks which the waves have scooped out. From 

 some study of this creature I am prepared to endorse the 

 view that his intelligence is of a high order, a fact which 

 one is prepared for, considering the mass and concentration 

 of bis nervous system. 



So far as the formation of the coral island is concerned, I 

 shall only refer to the action of forces that may now be ob- 

 served in operation on even this small kej-. This island 

 has increased in one direction, within the memory of the 

 inhabitants who have reached the age of fifty, by some thirty 

 yards. Beach formation, the work of the waves in grinding 

 and comminuting the dead remains of corals, mollusks, crus- 

 taceans, etc., will account for this, probably without the 



