39 



western shores of America, where the Chitons, some fifty or sixty specie?, 

 are more abundant than in any other part of the world, not a single Chi- 

 tonellns has been taken. At the Philippine Islands, on the other hand, 

 where Chitons are scarce, the largest species of Chitonellus known was 

 found by Mr. Cuming in plenty, and of extraordinary dimensions. They 

 were found dwelling in holes and cavities, either of natural formation or 

 bored by other mollusks, into which they force themselves by attenuating 

 their bodies in a manner truly surprising. At the Island of Zebu, where 

 Mr. Cuming met with a number of C. fasciatus, he found them partially 

 or entirely imbedded in holes and circuitous crevices of the coral reefs, 

 sometimes turned completely at a right angle, and at an angle again. 

 Many that were only partially imbedded, from having thrust themselves 

 into holes not deep enough to contain them, hung down with the posterior 

 end of the body fat and swollen, and whenever any force was used to with- 

 draw them, it invariably broke off. Mr. Cuming did not find the Chito- 

 nellus fasciatus under any other circumstances, and could only obtain spe- 

 cimens entire by splitting the coral and taking them from their hiding 

 places, in which they would be attenuated to the length of a foot and more. 

 Higher up among the islands of the Corean Archipelago, C. fasciatus was 

 found by Sir E. Belcher and Mr. Adams under stones; and, unlike the 

 Chiton, it would crawl away, on turning up the stone, at about the pace of 

 our common garden snail. Some interesting species have been collected 

 in Australia of smaller size, with the valves less isolated. 



The Australian and Tasmanian species are smaller, and the valves, cha- 

 racterized by a more elaborate variety of sculpture and colour, are broader 

 and less removed from each other. 



Species. 



1. fasciatus, Quoy. 4. larviformis, Blainv. 6. rostratus, Reeve. 



2. Gunnii, Reeve. 5. oculatus, Quoy. 7. striatus, Lam. 



3. laevis, Lam. 



Figure. 



Chitonellus fasciatus. PI. 25. Pig. 149. Animal, much contracted 

 from being dried, head downwards, showing the shell imbedded in 

 the substance of the mantle ; the valves isolated from one another, 

 approximate towards the head, and are become worn from the friction 

 arising from the habit of the mollusk of thrusting itself into holes 

 and crevices of rocks. 



