Boone, Mollusca, Cruises of "Ara" and "Alva" 321 



intercostal area is marked on the outer two-fifths of each of the 

 rays by a distinctive low ridge, unornamented, linear, which be- 

 comes less distinct, or obsolete, toward the umbonal region. 



Interior of valve : The right valve bears seven teeth or ridges, 

 separated from one another by a space of width and depth equiva- 

 lent to that of one ridge ; these being arranged in close series, on 

 the inner margin of the right side of the valve, along the curve 

 immediately below the auricle. The internal margin of the valve 

 is exquisitely crenulate, repeating in light and dark shades of 

 lavender-reddish-rose a maculated pattern banding the outer mar- 

 gin, followed on the inner side by a wider band of deep purple, 

 which is replaced by a lilac-lavender in the central portion of the 

 valve. 



References: Pecten zealandiae, Gray, J. E., in Appendix, to 

 DiEFFENBACH, E., Travels in New Zealand, with contribu- 

 tions to the geography, geology, botany and natural history 

 of that country, 1843, vol. II, Fauna, Appendix, Mollusca, 

 p. 261. 



Pecten dieffenbachi, Reeve, L., Conch. Icon., 1855, vol. VIII, pi. 

 22, figs. 88a-b, text on page opposite to pi. 22. — Hutton, F. 

 W., Cat. Marine Mollusca, Wellington, N. Z., Colonial Mu- 

 seum Geol. Surv. Dept., 1873, pp. 81 and 82. 



Family: SPONDYLIDAE 



Genus: SPONDYLUS Linne 



Spondylus nicobaricus Chemnitz 



Plate 133 



Type : This was collected in the East Indies. Present deposi- 

 tory not located. 



Distribution : This species is rather widely distributed in the 

 Indo-Pacific littoral zone. It has been reported from the East 

 Indies (Chemnitz, Kobelt) ; the Philippine Islands (Cuming, 

 Reeve), and the Queensland coast (Hedley). 



