CHITONS. 33 



being detached, they instantly become alarmed, the 

 shelly valves bend more downward, the leathery 

 mantle clings to the surface, and the muscular adhe- 

 sion of the foot becomes so great that no force can 

 now detach the animal, short of that which would 

 destroy the specimen. The approved mode of pro- 

 ceeding is as follows. Take an old rounded table- 

 knife, with which the collector should be provided, 

 in the left hand, so that the tip of the blade shall be 

 close to one extremity of the Chiton, without touch- 

 ing it. Then, with the palm of the other hand, as a 

 mallet, give a smart blow to the handle, the effect of 

 which will be that the animal is pushed from its hold 

 before it has time to be alarmed. In the present 

 case, however, this device was impracticable ; for, 

 owing to the very carious surface of the rock, and the 

 Chitons generally fiUing a hollow, it was impossible 

 to push them off. But I found that by suddenly 

 inserting the dull point of a strong pocket-knife 

 under the margin of the mantle, and giving a quick 

 wrench, I could remove them with facility, and gene- 

 rally without cutting or tearing the edge. Out of 

 more than fifty specimens which I essayed, I did not 

 lose more than two or three. Yet the operation was 

 not without difficulty, from the very sharp projec- 

 tions of the rock, and the force of the surf, which 

 frequently dashed violently over my head, and once 

 or twice knocked me down. I had to catch the 

 momentary intervals of the waves, to dislodge my 

 booty ; and sometimes a sea coming at the moment 

 I had done it, washed it from my grasp. The finest 

 specimens were found on the seaward side, and on the 



