218 AKISTOTLE S ANAIMA, 



from species of Murex and Purpura. Aristotle gives a 

 rather full account of the preparation of a similar dye from 

 his Porphurai. The pigment, he says, appears to extend, 

 like a duct or vessel, through a white membrane between 

 the mecon (or liver) and the neck, and when this membrane 

 is taken away and squeezed the pigment wets and stains the 

 fingers.* The small shells, he says, are pounded up without 

 removing the molluscs, because these are not easily removed, 

 but the molluscs are removed from the large shells, and the 

 pigment taken out.! 



The pigment is found, very much in the way Aristotle 

 says, near the hinder part of the neck, and lies in a duct or 

 vein there. It is of about the consistency and colour of 

 cream before exposure to the air, which changes it to a 

 purple tint. 



A gastropod, called by Aristotle Nerites, cannot be satis 

 factorily identified. He says that it has a smooth, large, 

 rounded shell, similar in form to that of the whelk, that its 

 mecon is red, and that some kind of crustacean sometimes 

 lives in its shell.! It would seem, from H. A. v. c. 13, s. 8, 

 that the Nerites lived attached to rocks, and, in a passage in 

 which he incorrectly asserts that all molluscs with spiral 

 shells have an operculum, he refers to that of Nerites.^ 



Prof. Forbes identified the Nerites with littoral forms 

 of Trochus, found abundantly along the rocky shores of 

 the ^Egean.H 



The above are the most interesting examples of 

 Aristotle s molluscs with coiled shells, in which, he says, the 

 flesh-like parts can be concealed to a very large extent. 11 

 From a series of passages, in H. A. iv. c. 4, s. 2, it is 

 sufficiently clear that he grouped molluscs which have 

 not coiled shells (stromboi) into univalves (monothura) and 

 bivalves (dithura) . 



Aristotle s typical example of his monothura is the 

 patella or limpet, called by him Lepas, which, he says, 

 has its flesh-like parts exposed,** and lives attached to 

 rocks, ft 



Of Aristotle s dithura, his Pinna, Kteis, and Solen will 

 be discussed. 



* H. A. v. c. 13, s. 4. f Ibid. v. c. 13, s. 5. 



| Ibid. iv. c. 4, s. 17. P. A. iv. c. 5, 6796. 



|| Travels in Lycia, &amp;lt;&c. t 1847, vol. ii. p. 110. 

 *l H. A. iv. c. 4, s. 1. ** Ibid. iv. c. 4, P. 2. 



ft Ibid. iv. c. 4, s. 18. 



