THE ANIMAL LIFE OF THE GROUP. 449 



Spiny Rock Shells. 



The extensive family -'* known as the spiny rock shells is represented in 

 Hawaii by ten genera with perhaps twenty-eight or more species. The typical 

 genus Murex is seldom found on the shore, but the genus Purpura, named in 

 allusion to a purple dye formerly secured from certain species, has three 

 species, one of which is quite common. These, together with the castor bean- 

 pod shells,-'' the banner shells ^" and the rattle shells ^^ shown in the plates, 

 will be sufficient to give an idea of the more common forms belonging to this 

 family. 



Of the rattle shells there are several small species known from Hawaii. 

 The mulberry shell ^- is appropriately named from its appearance. It is quite 

 generally distributed, but is not conspicuous, since it is less than an inch in 

 length. To these, and in fact to the great majority of shells of the same 

 general shape, the Hawaiians gave the class name pupu. It seems that the 

 number of species was so great that the natives applied specific names to only 

 a few of the more important ones. 



Tritons. 



The tritou family"-^ is represented in the islands by a dozen or more 

 species belonging to the typical genus ^^ and as many as eight or more of the 

 frog-shell ^^ group, which differ from their cousins in having a pronounced 

 ridge or varix on each side of the shell, which forms a thick ridge on the oppo- 

 site sides making the shell distinctly' two-edged. They live on the coral reef, 

 and all but one of the species has been taken from Honolulu harbor. 



The fine tritou trumpet ^'' is seldom taken on shore. But as they grow to 

 splendid proportions and are the largest shell that occurs in Hawaii and were 

 used by the ancient Hawaiians as a war trumpet, the.y are worthy of special 

 mention. They are said to attain a length of eighteen inches, but specimens 

 a foot in length are more commonly seen. Such shells are treasured as a real 

 possession by the old Hawaiian fishermen, for they know how scarce they are 

 and how hard they are to secure, living or dead. 



The hard shell has a jieculiar resonant quality. When the tip of the spire 

 is cut or gi'ound away and tlie shell used as a bugle (pu), it emits a peculiar 



Description' op Plate. 



1. Amastra violacece var. wailauensis. 2. Carelia sinclairi. .■?. Liiniimlln i/niriihi. 4. 

 Laminella gravida. 5. Amastra turritella. 6. Laminella snnfiu'nu n. 7. Amoslni rnhrifiin- 

 <la. S. Amastra tcxUlis. 9. Newcomhia canaliculata var. wailauensis. 10. hrptiu-haliiia sp. 

 11. Partulina diihia. 12. Perdicella fulgurans. 13. Laminella vemtsta. 14. Auriculella sp. 

 15. luidodoiita sp. Ifj. Succinea sp. 17. Helicina sp. 18. Pupa sp. 19. Pterodiseus rex. 

 20. Endodoiiia sp. 21. Philanesia haldtvini. 22. Eulota similaris. 23. Opeas pyrgiscus. 

 24. Succinea sp. 25. Leptachatina chrysalis. 26. Pterodiscus discus. 27. Philanesia sp. 

 28. Amastra frosti. 29. AchalineXla (Apex) lorata. 30. Partulina confusa. 31. Salimella 

 hacca. 32. Achatcnallastrum phnuata. 



