194 HELIX. 



3 toothed ; one of the three on the pillar lip, 

 other two on the outer white lip. Breadth about 

 half an inch. 



alternately (striped snail,) shell somewhat convent* 

 striped with alternating rays of a light and 

 dark colour ; whorls five, crossed by equi-dis- 

 tant raised lines ; lip curved, with a pearly hue 

 within; umbilicus large. Breadth about three- 

 fourths of an inch. 



glxiphyra, (shining snail,) shell much depressed, 

 smooth, pellucid, thin, fragile ; whorls five, 

 rounded, obsolete irregular cross wrinkles ; 

 whitish beneath ; umbilicus middling. Breadth 

 about half an inch. 



Section B. FLAT- ORBED HELIX, or PLANORBJS 

 ofBraguieres. Spire depressed or sunk, so as 

 not to be raised above the central plain of the 

 whole coil. 



si (short-tail snail,) shell sinestral (coiling 

 from left to right, beginning at the tip of the 

 spire, when the back of the animal is upwards,} 

 pale yellow, .brownish chesnut; somewhat keel- 

 ed above and beneath, particularly in the young 

 state ; whorls three or four, with raised, equi- 

 distant, fine cross lines ; spire concave ; aper- 

 ture large, bluish- white within ; umbilicus large. 

 Largest breadth about half an inch. Sometimes 

 it is a little larger, very dark coloured, with a 

 reddish mouth within. 



bicarinatus, shell sinistral, pale yellow or brown- 

 ish, somewhat keeled above and translucent be- 

 neath ; spire retuse-umbilicate, forming a cavi- 

 ty as deep as that of the base ; aperture large, 



