26 THE AMERICAN ARBACIA 



be found in Dahremberg, Saglio, and Pettier (1904, t. Ill, part 2, 

 p. 21 16). Imprints of sea urchins were stamped on ancient coins, e.g., 

 from Segesta and Teos (see Plate VIII, Figs. 42, 43 of Imhoof-Blumer 

 und Keller, 1889). 



In architecture, a part of the capital of a Corinthian or other column 

 is known as Echinus (see Oxford Dictionary). 



Necklaces of sea uichin shells were apparently used in olden times, 

 as pictured by Klein (1734). 



Use of fossil sea urchins by oil companies and as amulets has been 

 described under Fossils. 



f. Use as Experimental Material 



Perhaps the most important use of sea urchins is as experimental 

 material for biological work. The extensive use of the eggs and sperm 

 is made evident by the large compendium which follows as Part IV of 

 this Monograph; this deals mostly with only one species, Arbacia punct- 

 ulata, and with investigations carried out almost exclusively at Woods 

 Hole. Experiments on other species done in Naples, Sweden, Denmark, 

 England and other places are equally if not more extensive. 



