in the Pacific, (S^c. 93 



valves parallel with the surface — adhering very strongly by 

 a coarse corneo-fibrous prolongation of muscle. It differs 

 somewhat from the byssus, properly so called, of the Mytil- 

 acea, which is produced at pleasure by the animal, may be 

 torn away without injury to it, and terminates in a sort of 

 receptacle at the base of the foot. Here the fibres proceed 

 from a thick, conical, tendinous mass, and though I have rea- 

 son to believe the animal has the power of detaching itself, 

 yet when it was attempted to pull one away from the rock, 

 in almost every case, the whole muscle was torn from the 

 body, inflicting a fatal wound. I have often pulled them off 

 in this way and left them on the reef, to see if they would 

 re-produce the byssus, but always found them dead the next 

 day. It is a little singular that the Tridacna, when im- 

 moveably imbedded, should continue to moor by as strong a 

 cable, as when free upon the surface it is exposed to the rude 

 assaults of the breakers. The manner in which they become 

 thus buried, seemed to require a word of explanation, because 

 this condition has been considered a proof of the rapid in- 

 crease of the coral, which it was imagined had thus covered 

 the shell subsequent to its attainment of full size, yet during 

 the animal's life. 



On all parts of the reef. Crustacea and Echinodermata are 

 met with in astonishing numbers and variety. The MoUusca 

 generally speaking, are less abundant as a whole. The pools 

 and gullies literally seem alive with beautifully painted fishes. 

 a bare enumeration of whose genera would almost fill a page. 

 Among these a large spotted Murasna was conspicuous for its 

 fierceness not less than size. It lurked under stones or in 

 crevices, and when molested, instead of retreating, darted 

 directly at the intruder, and unless promptly avoided, inflicted 

 a most formidable bite. It moved with exceeding rapidity, 

 sometimes scuttling over the coral, sometimes making a suc- 

 cession of horizontal leaps from the water, of a couple of yards' 

 length. I have seen, at the attack of one, a whole boat's 

 crew flying in terror, who would fearlessly chase the numer- 

 ous sharks infesting the edges of the reefs and lagoons, till up 

 to their breast in the water. 



