The Olive Shells. Rice Shells. Harp Shells 



border, and the same wavy edge is shown by the ribs, and the 

 undulating pattern that decorates the spaces between. The width 

 of the ribs is usually unequal, but the greatest number of them 

 are quite narrow; the crenations form a series of spinous tubercles. 

 Colour, blue gray, festooned between ribs with black. Ribs, 

 chestnut, banded on pale ground. Found in muddy sand in deep 

 water. Length, 2 to 4 inches. 



Habitat. — Panama. 



The Slender Harp (H. gracilis, Brod. and Sby.) is least of all 

 and slim, with flat ribs far apart, delicately semi-transparent, and 

 tinted and variegated with gray and rose, accented with bright 

 red hair lines. Length, i^ inches. 



Habitat. — Polynesia. 



The Lesser Harp {H. minor, Lam.) is slightly larger than H. 

 gracilis, more square shouldered, decidedly darker. The narrow 

 ribs are crossed with black lines in pairs. Wavy longitudinal 

 markings of brown streak the spaces between ribs. 



Habitat. — Indian Ocean. 



T,he Conoid Harp {H. conoidalis, Lam.) is the most variable 

 species. Its elevated spire and broad sloping shoulders, are con- 

 stant characters. The ribs are narrow, rounded and distant. 

 The colour scheme is brown in many shades, the pattern like the 

 banding of an agate, crossing the ribs and festooning the inter- 

 stices. Often the patterns are blurred, but the eifect is very rich. 

 Length, 3 to 4 inches. 



Habitat. — Mauritius, Indian Ocean, Philippines. 



99 



