322 Bulletin Vanderbilt Marine Museum, Vol. VII 



Material examined : The "Alva" secured one large lime-en- 

 crusted specimen, another smaller specimen, supporting a vase 

 sponge and two lower valves (upper valves missing), from the 

 reef. Falcon Island, Palm Islands, Queensland, October 7, 1931. 



Technical description : The largest "Alva" specimen is not 

 quite as large as the one figured by Reeve, plate 14, figure 50, and 

 is somewhat encrusted by calcareous algae. The second specimen, 

 shown in plate 133, has the scales or spine-like teeth less eroded. 



The shell is attached, inequivalve, slightly auriculated, the 

 lower valve being frequently irregularly developed, the hinge area 

 very large, flat, becoming more prominent with age. There are 

 two solid reflected teeth in each hinge ; these are very powerful, 

 interlocking firmly, the ligament being inserted between them. 



The upper valve is ovate, convex, moderately inflated, with 

 twenty-four to thirty radiate striations, each beset with numerous, 

 obliquely erect, acute triangulate scales or spine-like teeth, some 

 of which are procurved and of varying sizes, ranging from ap- 

 proximately one-eighth to three-eighths inches long, forming a 

 thorny covering over the entire upper valve, including the auricu- 

 lar region. 



References: Spondylus nicobaricus, Chemnitz, J. H., Conch. 

 Cabinet, 1780-95, vol. VII, pi. 45, fig. 469, 470.— Chemnitz, 

 J. H., u. Martini, F. H. W., Syst. Conch. Cab., Nurnberg, 

 1888, Bd. VII, pi. 4, fig. 3, u. pi. 9, figs. 2, 3. 



Spondylus nicobaricus, Reeve, L., Conch. Icon, 1856, vol. IX, pi. 

 14, fig. 50 and text opposite. — Hedley, C, Rept. 12th Meeting 

 Australasian Assoc. Adv. Sci., 1909, Proc. of Sect. D, Marine 

 Mollusks of Queensland, 1910, p. 345. 



