NERITA. NERITE. 125 



others ending in a fine point, and placed somewftat late- 

 rally : aperture oval or halt-moon shaped ; the outer mar- 

 gin very thin ; pillar-lip reflected, forming a large and deep 

 perforation behind it : length sometimes an inch and a 

 half; breadth rather less. 



Variety A. With the volutions more produced to a point, 

 and without the coloured markings. 



Nerita Itcvida. Lister, pi. 569. f. 20 Lask&y, JVern* 

 Soc. i. p. 409. 



Variety B. Highly polished, with the volutions flat and 

 hardly distinguishable, more elongated and sloping to a fine 

 point, of a white color shaded with pale carnation; the first 

 marked with five rows of arrow-shaped crimson spots, one 

 row of which continues round the base of the lesser ones, 

 the fourth and sometimes the third chain consisting of 

 short oblique lines ; the outer-lip with an oblong crimson 

 patch behind it : length three-quarters of an inch ; breadth 

 half an inch. 



This variety is so different in its contour and markings 

 from the N. glaucina of the same size, that we are much in- 

 clined to think it a distinct species. It is found plentifully 

 in Dublin bay, always preserving its separate character. 



On most sandy coasts, v. v. 



3. Nerita Canrena. Bonnet Nerite. Fig. 71* ?- 

 Lister, pi. 560. f. 3, 4, pi. 564. f. 1 1. 



Nerita intricata. Donovan, pi. 1 67- 



Shell exactly resembling N. glaucina, but is more pro^ 

 duced and pointed ; and the perforation is furnished with 

 two spiral ridges, making it gibbous and cloven : length 

 half an inch ; breadth rather less. 



On the Western coast : very rare. v. m. 



4. Nerita Mammilla. Nipple Nerite. 

 Li*ter,pl. 571. f. 22, and pt. 566. f. 14. 

 Nerita nitida. Donovan, pi. 144. 



Shell oval-oblong, glossy, white or yellowish : ?pires five, 

 short, flat, and hardly defined, the suture being nearly ob- 

 literated : aperture oval, the perforation being nearly or 

 quite closed by the gibbous protrusion of the pillar-lip : 

 M 3 leogth 



