UNIVALVES. 



PLATE IX. 



Gems. POLYPLEX. 

 Character, Shell spiral, protuberant, having many folds or plicae, thickly placed 

 on the spire, body, and beak ; mouth round, and slightly angular, ending gradually 

 in a channel. . 



Species. 



No. 1. Polyplex purpurascens. Shell tuberculous, of a green colour; mouth 

 purple, with deep stripes of black ; the cheek angular and protuberant. 

 This curious shell is found plentifully upon the coasts of Tyre and Sidon, 

 and is undoubtedly the one which yielded the celebrated Tyrian dye of the 

 ancients ; the fluid which formed this dye is contained in a small vesicular 

 bag. Delineated from a specimen in Lord Valentia's Museum, which was 

 brought over by his Lordship from the Mediterranean Sea. 



No. 2. Polyplex rugosus. Shell brown, tuberculous ; the mouth rather narrow, 

 acuminated, white, inclining to purple. Drawn from the Collection of 

 Mr. Cracherode, now in the British Museum ; it is rare, and a native of 

 the Southern and Pacific Oceans. 



No. 3. Polyplex crenatus. Shell yellow, formed into longitudinal folds ; the 

 mouth white, shaded with brown. Native place unknown. From a speci- 

 men in the Author's Museum. 



No. 4. Polyplex gracilis. Shell white, shaded with brown, of a very elegant 

 form. This beautiful shell is found upon the coasts of New Zealand. 

 From the Museum of Mr. Humphrey. 



No. 5. Polyplex bulbosa. Shell white, shaded with brown; the mouth dark 

 brown ; the body richly foliated, and decussated. This shell differs ma- 

 terially from the former in the ridge of the mouth, and the line of the 

 body, the form of which is beautifully undulated. A native of the Indian 

 Seas. 



REMARKS. 



The genus Polyplex (so denominated from its numerous folds or membranaceous divisions), 

 is remarkable rather for its singularity than beauty. Though the species of this genus at 

 present known are very few, yet these are so distinctly marked by the most obvious and in- 

 dubitable characters, as absolutely to require a new and distinct genus; but, it is possible, 

 that by the recent discoveries in the southern regions of the globe, where this shell is chiefly 

 found, many more species may perhaps be brought to Europe, which will be highly inte- 

 resting to the future Conchologist, and the reader will now easily recognize, by the present 

 genus, under what head he is properly to class them. 



