CHAPTER XXX: THE THORNY OYSTERS 



Family SpoNDYLiOiB 



Genus SPONDYLUS, Linn. 



Shell irregular, attached by right valve, rarely free; valves 

 radiately ribbed, set with spiny or leaf-like scales; hinge of two 

 curved, interlocking teeth in each valve; mantle open; gills 

 separate; foot small, cylindrical. Inhabits warm seas. Living 

 species seventy; fossil eighty. 



The thorny oysters were known by name, admired and 

 eaten by the early Greeks long before most shell families had 

 been discovered. The warm Mediterranean shores harboured 

 the royal-hued Ass's Foot Spondylus, S. gcedaropus, Linn., and 

 others. The Swedish systematist retained the name given it by 

 Aristotle, who saw under the sharp prickles and curving flat 

 spines two valves shaped like a compact little hoof. 1 he purple 

 of the upper valve contrasts oddly with the orange that is mingled 

 with white on the under valve. The combination is peculiarly 

 rich and attractive. 



Collectors have always desired to have these showy bivalve 

 shells. They are all striking in ornamentation and colouring. 

 Even the distortion of form that results from their crowding as 

 they grow, attached firmly to rocky formations or to other shells, 

 adds interest, for it tells something of the life they live. 



We shall not find any species nearer than the Bermudas and 

 West Indies, Mexico and the Gulf of California. The adjectives 

 before their names will indicate the striking character of some of 

 the species : dyed, variegated, painted, strawberry, orange, yellow, 

 crimson-dyed, amber, dusky, violet, white-spined, many-spined, 

 bearded, cat's tongue, leafy, hedge-hog, porcupine, branched, 

 fingered, crumpled. Some aristocrats are called royal, princely 

 and imperial. 



The Variable Thorny Oyster {S. varians, Sby.) is great in 

 size and thickness, weighing several pounds. Its oval valves, 



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