36 



HELICID^. 



This shell may be classed with the former three, in 

 conjunction with which it is frequently found, as hav- 

 ing very much the same habits, and living in the same 

 localities. It is generally about three-fourths of an 

 inch in diameter, but varies in size, the average diame- 

 ter being little more than half an inch. The umbilicus 

 is large and deep. It may be distinguished from 

 virgata, in being much more depressed, having the 

 umbilicus much larger and deeper, distinctly exhibiting 

 the second and third whorls, and the outer volution 

 and mouth smaller and more cylindrical ; it is also 

 destitute of the rufous colouring within the lip of the 

 shell. 



Hah. Limestone districts and sands near the sea. 

 Generally distributed. 



H. OBVOLUTA. Muller. PI. VI, fig. 21. 



Shell orbicular, a light amber brown colour ; spire rather concave j 

 umbilicus spread, deep ; lip reflected and white. 



This shell does not resemble any of our other British 

 species in appearance, and it is questionable whether it 

 is really indigenous. The aperture is trigonal or foot 

 shaped, with a reflected white lip. It differs from 

 lapicida, which is perhaps its nearest ally, in being 

 smaller, of a different colour, having the whorls more 

 clearly defined and concave, and being neither keeled 

 nor much rounded at the circumference. The peculiar 

 shape of the mouth will readily distinguish it from any 

 of the other Helices. Diameter nearly half an inch. 

 Animal a dusky colour, head and tentacles black. 



Hah. The only recorded localities in which this rare 

 shell has been found, are among moss at the roots of 

 trees in Ditcham Wood, near Brenton, Hants, and along 

 the chalk escarpment of the South Downs. 



H. LAPICIDA. Linnceus. PI. VI, fig. 16. 



Shell orbicular, depressed ; grey or pale rufous, with darker radia- 

 tions ; sharply carinated at the circumference. 



The peculiar traits in this shell are, the depressed, 

 and when taken together, regularly curved whorls. 



