MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 55 



5. Littorina petrcea. — Shell globoso-conical, rather 

 thin, with the spire shorter than the last turn, which is 

 very convex, transversely rugoso-striate ; the aperture 

 roundish, the outer lip united at a rather acute angle. 

 Pet r (Bus, living on or among rocks. 



6. Littorina Beanii. — Shell globoso-conical, obtuse, 

 of three convex turns, the last very large, somewhat 

 glossy, faintly striated transversely and longitudinally, 

 and marked with alternate dark-brown and white lines 

 disposed in a tessular manner. Named after Mr. Bean, 

 a Yorkshire naturalist. 



7. Littorina neritoides. — Shell subglobose, thick, with 

 the spire depressed and rounded, the aperture round- 

 ish-ovate, the colour various. Neritoides, resembling a 

 Nerita. 



Genus 5. Turritella. — Shell turrite, with the spire 

 very elongated, tapering to a fine point, the aperture 

 roundish, entire, with the peristome incomplete behind, 

 the outer lip very thin, and having a wide sinus. Name 

 from Turris, a tower. Lamarck. 



1 . Turritella Terebra. — Shell turrite, acuminate, with 

 from fifteen to twenty moderately convex turns, each 

 with three longitudinal narrow ridges, and curved trans- 

 verse lines. Terebra, an auger or wimble. 



Genus 6. Eulima. — Shell turrite, with the spire very 

 elongated, tapering to a fine mammilliform point ; the 

 aperture ovate, entire, with the peristome incomplete be- 

 hind, the outer Up thick and even. Risso. 



1. Eulima elegantissima. — Shell turrite, very elon- 

 gated, of numerous, flat, transversely grooved and obtusely 

 ridged turns. Elegantissimus, very elegant. 



2. Eulima nitidissima. — Shell very elongated-turrite, 

 of about nine rounded, smooth, glossy turns ; the aper- 

 ture subovate, with the outer lip thick. Nitidissimus, 

 very glossy. 



3. Eulima polita. — Shell very elongated-turrite, taper- 

 ing to a fine point, of about ten flat, smooth, very glossy 



