12 



brilliancy and iridescence, glowing with all the colours of the rainbow. 

 Attention must, however, be given to the outer crust of the shell for the 

 discrimination of species. The varieties of situation and tubular excres- 

 cence are often very characteristic. The number of perforations varies in 

 different species, but, as we have just stated, they are alike in individuals 

 of the same species; where an exception occurs, it is that there are some- 

 times one, or at most two, less in the adult than in the young shell. When 

 the animal is growing it has one or two holes open in arrear of the number 

 required, and on reaching maturity the holes are filled up. 



It is a curious circumstance in the geographical description of the Ha- 

 liotides, that few, if any, are to be found where Chitons abound, as if they 

 exchange places to a certain extent in the two hemispheres. There are a 

 few species of Haliolis in California ; but along the western coast of South 

 America, where Chitons are most abundant, not a single species has been 

 observed; and only one small species, H. pulcherrima, has been collected 

 at any of the islands of the Pacific. They inhabit the shores cf China, 

 Japan, Ceylon, Mozambique, the Cape Colony, Borneo, and the Philippine 

 Islands ; but the greater number, and most striking, of the species are 

 from New Zealand and Australia, displaying all that speciality and strange- 

 ness of design which is so characteristic of the general natural history of 

 those colonies. The nearest approach of the genus to our own shores is 

 in the H. tuberculata of Guernsey, which is sold in the fish-market as an 

 article of food.* They are found at low water attached to the under-sur- 

 face of fragments of rock, and on the least alarm they fix themselves by 

 suction with the force of a Limpet. 



1. albicans, Quoy. 



2. ancile, Reeve. 



3. aquatilis, id. 



4. asinina, Lin. 



5. astricta, Reeve. 



6. bistriata, Gmel. 



7. Californiensis, Swain. 



8. clathatra, Reeve. 



9. coccinea, id. 



10. coccoradiata, id. 



11. concinna, id. 



Species. 



12. corrugata, Gray. 



13. Cracherodii, Leach. 



14. cruenta, Reeve. 



15. Cunninghami, Gray. 



16. discus, Reeve. 



17. diversicolor, id. 



18. Dringii, id. 



19. elegans, Koch. 



20. Emmse, Gray. 



21. excavata, Lam. 



22. funebris, Reeve. 



23. gemma, Reeve. 



24. gibba, Phil. 



25. gigantea, Che in. 



26. glabra, id. 



27. incisa, Reeve. 



28. iris, Gmel. 



29. Jacnensis, Reeve. 



30. Janus, id. 



31. Japonica, id. 



32. Kamtschatkana, Jonas. 



33. lamellosa, Lam. 



* While dining one day with a well-known naturalist and antiquary of Guernsey, Mr. F. C. 

 Lukis, an entremet of Haiiotis tuberculata was served. I had understood they possessed the 

 delicacy of a veal cutlet, but on endeavouring vainly to masticate one, they reminded me more of 

 what might be the taste of a dish of little duodecimo Latin grammars. 



