THE ANIMAL LIFE OF THE GROUP. 461 



are represented in Hawaii l)y two species, there being but fifteen species 

 described. The partridge tun -^ is the more common, though a specimen is a 

 real prize. It is fairly typical of the family. The tun is a large shell with a 

 stout spire and swollen body-whorl that is banded by strong spiral ribs. Tlie 

 shell is marked with crescents and irregular lines of white on a rich brown 

 ground color, suggesting the breast of a partridge. They are said to attain a 

 length of fifteen inches, but the specimens found on the beach are seldom more 

 than a third that size. The black-mouthed tun -** is much rarer. It is dirty 

 white in color and has the outer lip dark brown. 



O.vMEO Shells. 



The helmet or cameo shells ''■' are active predatory moUusks that live 

 along sandy shores in the warm seas. There are perhaps three dozen species 

 and sub-species, of which five or six are known to occur in the waters about 

 Hawaii. They all agree in being thick, heavy shells with short spires. The 

 aperture is long and ends in a recurved channel. The typical horned helmet ^^ 

 occurs in the islands. Although it is a rare shell here, it is of more than ordi- 

 nary interest since it is one of the shells used elsewhere in the manufacture 

 of cameos, cutting a white figure on an orange-brown ground. It is the giant of 

 the family, reaching a foot in length. The shell is yellowish-white tinged with 

 yellowish-brown, and is studded over the back with three rows of tubercles. 

 Blotches of dark brown occur on both the curiously expanded lips and on 

 the knobs. 



The more common form on Oahu is Cassis vibex, which has four short 

 spines at the base of the lip and is seldom more than three inches in length. 

 It is a fiesliy-ash color, obscurely banded and varied with light and dark chest- 

 nut. The lip on its outer margin is marked with chocolate spots. A variety ^i 

 also occurs that is smaller, thicker and has small elongated tul>ercles on the 

 shoulder. 



i\IooN Shells. 



In the family of moon shells, or naticas,''^ the shell is more or less globular 

 or ear-shaped and the aperture differs from that of the preceding families in 



(Description of Plate Continued, from Opposite Page.) 



pilearis). 4. Quilted Triton {Triton tuherosus). 3. Spindle Shell (Fusus nmxF-liollandia'). 

 6. Chocolate-lined Cone {Coiius quercinws). 7. Lettered Cone (Conus puUcarius). 8. He- 

 brew Cone (Conus hebrwus). 9. Co««.s Uvidus. 10. Conus miliaris. 11. Anger shell sp. 

 (Terehra sp.). 12. Terebra gouldi. 13. Teiebra oculata. 14. Terebra acicuJiiw. 15. 

 Hermit Shell {Cassis vibex var.). 16. Hawaiian Top Shell {Trochus sandtciffn.<!is). 17. 

 Hump-backed Cowry [Leho] {Cyprwa mauritiana). 18. Cyprwa reticulata. 19. Turban 

 Shell {Turbo chry.iostomus) . 20. Turbo intercostalis ; showing the operculum in place. 21. 

 Cyprcea sulcidentata. 22. Worm Shell [Pohokupele] (Vermetus sp.). 23. Vermetus sp. 24. 

 Kaunna {Trrmetus sp.). 1^. Partridge Tun [Puonionio] {Dolinm perdix). 2(i. Umbrella 

 Shell |()pihi kapiiailio] {ndrionisnis eiaratus). 27. Coiinid Harp Shell (Ilarpd ronnidoli.i). 



