OCINEBRA. 117 



The animal has a yellowish body, mottled with white, with 

 slender, tapering, orange-colored tentacles, and eyes on long- 

 stalks exterior to and united to the tentacles for two-thirds their 

 length ; foot small, nai-row, rounded in front, pointed behind, the 

 sole with a slight median groove ; gills very small, brownish ; 

 tongue cylindrical, ratlier long, the teeth shown in fig. 58, pi. 5. 



Like Purpura lapillus, this animal yields a purple dj^e, but the 

 tint is variable. Its egg-cases are attached in clusters of 15 to 

 150 to shells and stones, and each case contains from 12 to 20 

 embryos. The cases are triangular, with compressed sides, and 

 the attaching stalks are short and narrow. 



The Marex erinaceus is a well-known depredator on the 

 oyster-beds of Europe, and is considered one of the most dan- 

 gerous enemies with which the ostreiculturist has to contend. 

 The English fishermen know it under the name of '' sting 

 winkle," and the French call it the "cormaillot " or " perceur." 

 So destructive is it in the oyster-pares of Arcachon (near Bor- 

 deaux) that it is incessantly hunted by the fishermen, who spend 

 whole days in destroying it by removing with a knife a portion 

 of the foot and the operculum, after which the animal is left to 

 die at its leisure or become the pre^^ of other carnivores. The 

 Murex seats itself firmly upon the shell of the oyster and applies 

 its rostrum to the surface of the latter, invariably at a 

 point near the beak ; after which a regular movement of the body 

 to right and left ensues during a term of three or four hours and 

 results in piercing a small, round hole through the oyster shell, 

 exposing the most essential viscera to the rapacity of the patient 

 tunneicr. It is believed that the denticles of the tongue are ap- 

 plied to the surface to be bored and then the gyration of the 

 animal gradually rasps through the hole ; it has been supposed 

 by some that an acid solvent is also used in this operation, but 

 this is only conjectural. M. Fischer* has observed at Arcachon 

 that young iMurices chose young oysters, whilst adults select 

 larger oysters. The bored oyster soon dies or else exhausted, 

 opens its valves, when a myriad of other animals : crabs, mol- 

 lusks, worms, fishes hasten to profit by the fruit of the winkle's 

 labor. Dr. Fischer says that the Murex only (at Arcachon) 



* Joui". Conch. 5, 1865. 



