opening and closing the two valves of the shell, thereby causing a click- 

 ing sound. The noise of several hundred of these clicking shells, and 

 the sight of as many of them with strings of seaweed attached to them, 

 looking not unlike a comet with a long tail, is quite bewildering. This 

 habit of shooting through the water has caused them to be called 

 ' dancing scallops.' In both Europe and America the scallop is con- 

 sidered a delicacy, and several tons are gathered annually. The scallop, 

 Pecten maximus, has a bright orange body and a fawn-colored mantle. 

 A related species, Pecten jacoboem, has been dignified as a badge of several 

 orders of knighthood, and it was also worn by pilgrims to the Holy Land, 

 many years ago. It was called St. James's Shell. 



"The family Spondylidcv is closely related to the scallops, and the 

 shells certainly rank as among the most beautiful and striking of all 

 bivalves. They are variously colored with brown, red, and white, and 

 are covered with many long, graceful, sharp spines-. In some species, 

 in adult life, the lower valve is attached like the oyster, from which 

 habit they have received the common name of ' spiny ' or ' thorn ' oyster; 

 but a few, like the Spondylus imperialis, in the center of this case, 

 remain free during life. The finest and largest specimens come from 

 the Gulf of California. 



"A family closely related to the Spondylidc/B is the Limidce, of which 

 the genus Lima is the typical form. The name Lima means a file, 

 and the shells are called * file shells,' because the surface is covered 

 with scaly ribs, giving it the aspect of a file. There are about twenty 

 species in the family, which are found in many parts of the world. 

 In early geological times they must have been very numerous, over 

 three hundred species having been found in the rocks of Europe, India, 

 and the United States. 



"Dr. J. Gwyn Jeffreys, in his ' British Conchology,' thus writes of the 

 Lima : i The Lima moves, or rather darts through the water like a scal- 

 lop, but in a contrary posture. The hinder, instead 

 of the ventral end is in front, so that the mode of its 

 progression may be compared to that of a fish swim- 

 ming tail foremost. Some species construct dwelling- 

 places called * nests ' out of fragments of shell, coral, 

 gravel, and other material, which they ingeniously 

 common Chinese tile- fasten together by their byssal threads and attach 



shell. (Tryon.) J 



to the roots of large seaweeds, beveral young ones 

 often occupy the same nest, or case, but when they become adult each 

 individual has a house of its own. This remarkable construction is fun- 

 nel-shaped, with the larger end contracted, and sufficiently wide to admit 



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