372 Shell Life 



almost triangular mouth with a tooth on the pillar 

 and one on the pillar-lip. P. anfjlica, found no farther 

 south than Herefordshire, measures only one-twelfth 

 of an inch, and has a semicircular mouth protected 

 by seven or eight teeth. P. inuscoviun is one-seventh 

 of an inch, has a white rib outside the lip, and a small 

 tooth on the pillar. Widely distributed south of 

 Scotland. P. edentula, of similar proportions to the 

 last, has a semi-oval mouth without teeth. Generally 

 distributed. P. ininutissima is similar to the last, 

 but smaller (one-twelfth of an inch), without teeth. 

 Recorded only from the Isle of Wight, south-west 

 Yorkshire, Durham ; Edinburghshire ; and Kerry. P. 

 alpestris, one-twelfth of an inch, lias a semi-oval 

 mouth with four or five teeth. It occurs onl}'^ in south- 

 west Yorks, south Northumberland, Westmoreland, and 

 County Londonderry. P. lilljehorgi, one-tenth of an 

 inch, globose, mouth semi-oval, with four equidistant 

 teeth, strengthened by a slight rib outside. Found only 

 in County Gal wa}^ P. nioulins iana, similar to the last, 

 but more barrel-shaped, and with a stronger rib out- 

 side lip. Found only at Otterbourne, Hants ; Hitchin 

 and Rye House, Herts. P. ];)yginc(3a, oval, one-tenth 

 of an inch, mouth strengthened by an outer rib which 

 protrudes slightly inside and from which spring two or 

 three of the four or five teeth. Common, and widely 

 distributed. P. siibstriata, one-twelfth of an inch, 

 mouth somewhat pear-shaped, with from four to six 

 teeth, two or three of which spring from a white rib 

 inside the outer lip. Occurs in Anglesey, Derbyshire, 

 south-west Yorks, Durham ; and County Londonderry. 

 P. antivertigo, one-twelfth of an inch, mouth half-oval 

 with from six to ten red-brown teeth, and strengthened 



