222 MANTTAL OF THE MOLLTJSCA. 



? EiNGiCTJLA, Deshayes. 



'Etymology, diminutive of ringens, from riiigo, to grin. 



Type, E. ringens, PI. V., Fig. 21. 



Shell minute, yentricose, with a small spire ; aperture notclied, 

 columella callous, deeply plaited ; outer lip thickened and 

 /Reflected. 



Distribution, Y species ? Mediterranean, India, Philippines, 

 Qallapagos. 



Fossil, 9 species. Miocene — . Britain, France. Ringicula 

 is placed with nassa by Dr. Gray and Mr. S. Wood ; it apjDears 

 to us yery nearly allied to cinulia = avellana, D'Orbigny) io 

 tornatellidce. 



PuEPtrRA (Adans.), Lam. Purple. 



Type, P. persica, PL YL, Fig. 1. 



Shell striated, imbricated, or tuberculated ; spire short ; 

 aperture large, slightly notched in front ; upper lip much worn 

 and flattened. Operculum lamellar, nucleus external. PL YI,, 

 Fig. 2. Lingual dentition like murex erinaceus ; teeth trans- 

 yerse, three crested ; uncini small, simple. 



Many of the purpune produce a fluid which giyes a dull 

 crimson dye ; it may be obtained by ^Dressing on the operculum. 

 P. lapillus abounds on the British coast at low water, amongst 

 sea-weed; it is yery destructiye to mussel-beds. (Fleming.) 



Distrilution, 140 species. West Indies, Britain, Africa, India, 

 New Zealand, Pacific, Chili, California, Kamtschatka. From 

 low water — 25 fathoms. 



Fossil, 40 species. Tertiary — . Britain, France, &c. 



Concholepas, Fayan. C. lepas (Gmelin sp^ies) PL YL, Fig. 3. 

 Peru. The only species difiers from purpura in the size of its 

 aperture and smallness of the spire. 



Cuma (Humphrey) P. anguHfera, inner lip with a single 

 prominent fold. 



? PuEPTJErN-A (Lycett, 1847), D'Orbigny. 



Shell yentricose, coronated; spire short; aperture large, 

 scarcely notched in front. 



Fossil, 9 species. Bath-oolite. Britain, France. The type 

 P. rugosa, somewhat lesembles pjiapura chocolatum (Duclos), but 

 the genus probably belongs to an extinct group. 



Ehizochiltts, Stp. 1850. 

 Example, R. antipathum. Founded on a species of Purpura ? 



